Disclaimer: This is going to be some dumb/newbie questions, so if you're not patient this is not a good thread for you, lol.

OK so after two years of acquiring sets I finally am getting around to recapping and retubing my first set. A Zenith b/w table top. I've been reading here, watching videos from shango and Doug, read the antique radio guides, etc.

These are my questions (based on the pictures below).

1.) There are two electrolytic cans that have three terminal leads each with different values. After scouring the net I am guessing these types of twist lock style cans are no longer produced. I have two NOS exact part # Zenith replacement cans. I understand the point is that it is not a matter of used/unused it is a matter of time drying out the electrolytes. But really, if I use these, will it be the same result as not even replacing the old ones?

2.) In the photos that show under the current can already installed, I noticed the electrolytic capacitor only has wires going to two terminals leaving one unconnected. The schematic shows all three having connections. I have had this set on before and it worked as is. So what is up with this? I am not good at reading schematics but it shows that particular empty terminal supposed to be going to near the horizontal hold. So confused.

3.) Do these old cans just twist off? It looks like I will have to break the old one somewhat to get it out.

4.) The picture with the tape on the tube with a grounded wire to the chassis. What is that? I discovered that when I removed the plastic backing and it looks like someone rigged something up there.

5.) On the electrolytic marked "2407031", I have a nice new electrolytic for this one but I noticed on the right side it looks like there are two wires going to the + side. When I solder in the new one it is an axial style. Should I just make sure both of them are making contact to the new lead?

6.) Lastly, please look at my paper/film capacitor assortment. Are these the right type? All the values are matching the old ones I just didn't know if they are acceptable types. They are going to replace the old wax/paper ones.

OK, if anyone is bored/feeling charitable please feel free to answer these questions.

PS, anything to help me not get shocked before I begin? Nothing is too obvious for a beginner. The set has been unplugged for over a year.

Thanks!!!!!!

(6) - Yes, suitable types. The only caution would be if the voltage ratings were lower than the original (they are most likely OK).

(5) yes, just connect both wires to the plus side of the new one.

(4) The conductive coating ("dag") on the outside of the tube MUST be grounded. This way the tube itself acts as a capacitor to filter the high voltage supply. If it's not grounded, the dag can charge up and arc to other things. It looks like someone fixed a loose or broken ground this way.

(3) and (2): Someone else more familiar should answer

(1) both time and temperature affect the degradation of electrolytic capacitors. So, the NOS might be better but still not good. Safest thing is to replace with new, especially if you have no way of testing them. It takes an old-fashioned tester that applies sufficient voltage to see if they are leaky. A modern low-voltage capacitance meter will not detect this.

PS: after a year disconnected, your only risk of shock is static from scuffing your shoes on the carpet. However, once you do fire it up, it's good to discharge both the lytics and the high voltage after you shut it off and before you go poking around.

Of course, don't do any work while it's plugged in. It's a good idea to UNPLUG the set (not just turn off a power strip) in case it is a hot chassis set (no power transformer) or is a transformer set that happens to have a short somewhere.

(6) - Yes, suitable types. The only caution would be if the voltage ratings were lower than the original (they are most likely OK).

(5) yes, just connect both wires to the plus side of the new one.

(4) The conductive coating ("dag") on the outside of the tube MUST be grounded. This way the tube itself acts as a capacitor to filter the high voltage supply. If it's not grounded, the dag can charge up and arc to other things. It looks like someone fixed a loose or broken ground this way.

(3) and (2): Someone else more familiar should answer

(1) both time and temperature affect the degradation of electrolytic capacitors. So, the NOS might be better but still not good. Safest thing is to replace with new, especially if you have no way of testing them. It takes an old-fashioned tester that applies sufficient voltage to see if they are leaky. A modern low-voltage capacitance meter will not detect this.

PS: after a year disconnected, your only risk of shock is static from scuffing your shoes on the carpet. However, once you do fire it up, it's good to discharge both the lytics and the high voltage after you shut it off and before you go poking around.

Of course, don't do any work while it's plugged in. It's a good idea to UNPLUG the set (not just turn off a power strip) in case it is a hot chassis set (no power transformer) or is a transformer set that happens to have a short somewhere.

I appreciate your reply. I will re-read it when I get home. Just quickly though with regard to the "DAG", now that I understand what it is, the coating is worn off in several blotches of the tube. Would it be prudent that I re-coat these areas (if that is even possible)?

I appreciate your reply. I will re-read it when I get home. Just quickly though with regard to the "DAG", now that I understand what it is, the coating is worn off in several blotches of the tube. Would it be prudent that I re-coat these areas (if that is even possible)?

Are you sure it's worn off, or could it be deliberately not applied in those areas? It should not be applied too close to the high voltage connector because of the possibility of arcing. (Of course, what is there should be contiguous so it's all grounded.) In any case, it's OK to wait until you have the set running to see if there is any problem. Aquadag (the full name) can be purchased and applied easily, but I wouldn't bother until you're sure you need it.

First thing is change the caps ONE AT A TIME ! Then recheck the
set & see if anything changed.

1) those NOS cans are OLD ! By the 70's they packaged them in just
plastic, not boxes. Since the set is running you may want to do them
last in this case.
2) it may be a subbed cap & there is another one hung in under there somewhere.
3) most Zeniths twisted 2 of the lugs & soldered the other 2 so breaking
off the twisted ones it will come out easy. You may need a very hot
iron such as the old classic Weller gun.
4) The CRT wasnt grounding good. Someone moused it to get by.
The GND is made either with a set of finger or a coil spring on the bottom.
Some use a very long, small spring across the DAG. If the DAG is chipping
off it can be replaced. Symptom are diagonal dots in pix, bad sync, sometimes hissing, sparkles & ozone smell. Can also radiate & bother other TV's radios etc.
5) not sure what you mean here.

Safety ! The most dangerous place is where the AC comes in. I never
heard of a tech dying from a TV HV shock. I got them once a week for
40 yrs. The filter cans in most sets will bleed off fast. The HV will stay
charged a LONG time with a tube rectifier. Avoid the base of the HV
rect tube & anode lead. If you discharge it it can build back up to a
lower level so discharge several times over a few minutes.

BTW Put up a few under chassis & chassis pixs & chassis ##

73 Zeno:smoke:
LFOD !

Are you sure it's worn off, or could it be deliberately not applied in those areas? It should not be applied too close to the high voltage connector because of the possibility of arcing. (Of course, what is there should be contiguous so it's all grounded.) In any case, it's OK to wait until you have the set running to see if there is any problem. Aquadag (the full name) can be purchased and applied easily, but I wouldn't bother until you're sure you need it.

Well I did notice it is not applied near the high voltage connector but I was thinking it was worn off due to the unevenness of it all. Toward the top it's chipping and peeling. After I recap it then perhaps I will see where I am with this aspect.

First thing is change the caps ONE AT A TIME ! Then recheck the
set & see if anything changed.

1) those NOS cans are OLD ! By the 70's they packaged them in just
plastic, not boxes. Since the set is running you may want to do them
last in this case.
2) it may be a subbed cap & there is another one hung in under there somewhere.
3) most Zeniths twisted 2 of the lugs & soldered the other 2 so breaking
off the twisted ones it will come out easy. You may need a very hot
iron such as the old classic Weller gun.
4) The CRT wasnt grounding good. Someone moused it to get by.
The GND is made either with a set of finger or a coil spring on the bottom.
Some use a very long, small spring across the DAG. If the DAG is chipping
off it can be replaced. Symptom are diagonal dots in pix, bad sync, sometimes hissing, sparkles & ozone smell. Can also radiate & bother other TV's radios etc.
5) not sure what you mean here.

Safety ! The most dangerous place is where the AC comes in. I never
heard of a tech dying from a TV HV shock. I got them once a week for
40 yrs. The filter cans in most sets will bleed off fast. The HV will stay
charged a LONG time with a tube rectifier. Avoid the base of the HV
rect tube & anode lead. If you discharge it it can build back up to a
lower level so discharge several times over a few minutes.

BTW Put up a few under chassis & chassis pixs & chassis ##

73 Zeno:smoke:
LFOD !

Thank you for the help. I am working on setting up a work area in the cellar then I can take more pics as I go. I don't want to open the set up again in my apartment as it is generally very dirty and crud always falls over the place.

No need to remove the FP cans from the chassis....Just disconnect the positive terminal leads from the can and it will remain electrically dormant and preserve the original above chassis appearance.

No need to remove the FP cans from the chassis....Just disconnect the positive terminal leads from the can and it will remain electrically dormant and preserve the original above chassis appearance.

I think I understand what you're saying. Leave it alone, disconnect it from beneath and put the new capacitor underneath. Neat idea. I have also read about rebuilding them and stuffing the new ones inside.

PS...If I forget the NOS Zenith stuff in the picture I will need the following:

1) 150uf-350v, 100uf-350v, 200uf-25v

2) 4uf-350v, 10uf-400v, 20uf-25v

I have been looking at all the major sites they don't seem to have capacitors with these three values each in 1 can. I was looking at that thread where the can went through the roof so I may want to avoid using the old and dried out NOS stuff after all.

You may need a very hot
iron such as the old classic Weller gun.

I'm finding that out now. I will have to pick up something more heavy duty for desoldering. For the normal soldering of the paper caps will a 30 watt soldering iron from Harbor Freight work? I seem to remember reading somewhere 40watt is the normal minimum.

I think I understand what you're saying. Leave it alone, disconnect it from beneath and put the new capacitor underneath. Neat idea. I have also read about rebuilding them and stuffing the new ones inside.

PS...If I forget the NOS Zenith stuff in the picture I will need the following:

1) 150uf-350v, 100uf-350v, 200uf-25v

2) 4uf-350v, 10uf-400v, 20uf-25v

I have been looking at all the major sites they don't seem to have capacitors with these three values each in 1 can. I was looking at that thread where the can went through the roof so I may want to avoid using the old and dried out NOS stuff after all.

For the most part, having 3+ sections in 1 can is something that died with FP twist lock style cans...It is fine/normal practice to use 3 individual caps to replace one 3 section twist lock. Most twist locks have the can as the common negative to each section. Some capacitance values like multiples of 2,3,4,5 are not made anymore and have been supplanted with 2.2,3.3,4.7,etc. You can fudge the capacitance values a decent bit and be fine. The original parts often had +100%/-50% capacitance tolerance so anything close in value capacitance wise will be fine.

Voltage you can only fudge upwards...The voltage rating of a cap is the max input voltage it can take without going bang(!)...If you replace a 150V with a 200V part the 200V can take more abuse before going bang. If you replace a 150V with a 50V the 50 will probably have ~100V on it and go bang quickly.

For the caps use
1) 100mfd & a 47mfd in parallal 450V
100mfd 450 V
220mfd 50V

2) 4.7MFD 450V
10mfd 450V
22mfd 50V

Thats all using modern values & a little extra on the voltage. Best
way to change is leave the old can in, Cut off wires & use a terminal strip.
Mount the new stuff close to the old ! Here is the style strip.

https://www.radioshack.com/products/radioshack-5-position-terminal-strip

73 Zeno:smoke:
LFOD !

Not too long ago I discovered that Mouser carries solder lug terminal strips by Keystone. I was surprised to see a vintage type of part there.
They have many versions with different number of lugs and in different arrangements. I've also gotten them from Radio Daze.
https://www.mouser.com/ProductDetail/Keystone-Electronics/817?qs=sGAEpiMZZMvz8LftK4jerkUaD0IcaHDhHpkXpfvzp08 %3d

A little hard to find on Mouser, search under "Keystone", terminals, lug terminals, terminal strips, solder type.

Thank you for the help. I am working on setting up a work area in the cellar then I can take more pics as I go. I don't want to open the set up again in my apartment as it is generally very dirty and crud always falls over the place.
One of the first things you should do is clean the chassis. Some of that dirt may be conductive and lead to problems. You can use compressed air if you are careful. Don't hit the speaker or the DAG with high pressure air for instance.
Another way is using a vacuum cleaner and a soft brush (paint brush). Don't suck the Dag off the CRT.
A limited amount of window cleaner can be used but don't go near the tube numbers. The tube numbers can sometimes come off if you touch them.
It would be better if you worked on some radios first to get the hang of things.

I'm finding that out now. I will have to pick up something more heavy duty for desoldering. For the normal soldering of the paper caps will a 30 watt soldering iron from Harbor Freight work? I seem to remember reading somewhere 40watt is the normal minimum.
30-40 W will do for most things. Things soldered to the chassis may take more, maybe 60W, but you don't have to remove the metal cased caps anyway most of the time. Also if a component lead is soldered to the chassis you can clip the lead near the old part and splice the new component lead to the old lead, no need for a big iron.

The cheapest iron at Wallmart will be fine for most PCB and light chassis work. If you can find a 75-150W cattle prod iron, those are awesome...You can make a chassis ground point wherever you want, normal terminals melt instantly, you can unsolder shield plates that are joined with solder easily, etc, etc...Joy to work with...Till you accidentally melt something plastic (the small ones can do that too).

One of the first things you should do is clean the chassis.

It's funny you mention that, I did just that! A lot of rust came off, chassis is now looking good.

I've discovered paper caps are pretty easy and straight forward - when there is enough room to work! Some of these caps have no lead length and are behind several layers of resistors and other parts. I guess the engineers didn't intend for anyone to be recapping 50 years in the future. I also have several books from the 60's and 70's and capacitors are never mentioned. I guess this is a very modern thing we have to do.

Thanks for everyones help. I will have about another 6 questions soon in case anyone else will want to answer and help out. Cannot wait to get done and turn on the TV and see if it works, lol.

Note: when cleaning the above chassis take care not to leave any rust, dag flakes, solder splash, other conductive stuff on those above chassis terminals... I've seen dag flakes burn up, and I've seen power resistors burn up from a solder blob short (that I made resoldering stuff in the HV cage). Those exposed terminals are great for troubleshooting till conductive crap lands on them...Then things go downhill fast.

By the 60's most 'paper' caps had mylar in them(as part of the paper dielectric layer) or were really full mylar caps. Most 60's and newer sets don't 'need' the paper caps changed since the mylar prevents leakage...Granted the paper/mylar sandwich types tend to drift in capacitance as the paper degrades which can be an issue.

Mid 50's and older sets (late 50's early 60's was the transition to mylar) used full paper dielectric caps and lit from the paper cap era does warn of bad caps...If you do 50's sets and know what stock caps and soldering look like, then you'll find many 50's sets had several paper caps changed when close to new.

Sets ~1964 and newer I don't change anything but the lytics unless I have confirmation/diagnosis of cause of failure.

Note: when cleaning the above chassis take care not to leave any rust, dag flakes, solder splash, other conductive stuff on those above chassis terminals... I've seen dag flakes burn up, and I've seen power resistors burn up from a solder blob short (that I made resoldering stuff in the HV cage). Those exposed terminals are great for troubleshooting till conductive crap lands on them...Then things go downhill fast.

By the 60's most 'paper' caps had mylar in them(as part of the paper dielectric layer) or were really full mylar caps. Most 60's and newer sets don't 'need' the paper caps changed since the mylar prevents leakage...Granted the paper/mylar sandwich types tend to drift in capacitance as the paper degrades which can be an issue.

Mid 50's and older sets (late 50's early 60's was the transition to mylar) used full paper dielectric caps and lit from the paper cap era does warn of bad caps...If you do 50's sets and know what stock caps and soldering look like, then you'll find many 50's sets had several paper caps changed when close to new.

Sets ~1964 and newer I don't change anything but the lytics unless I have confirmation/diagnosis of cause of failure.

oh, wow so what am I recapping then? This set is from the late 60's or early 70's. I assumed it was customary to swap out all the capacitors with any old set. By the way, I should be more clear with my terminology. I think I am using the wrong term. When I say paper caps, I think they aren't really paper, more film drop type. I might open this thing up again soon, I will take some pictures. I am trying to come up with a game plan for the electrolytics currently.

It is usually customary to state more specifically what you are working on (model) and generally make each thread about that item.
Some of us here online are a bit rusty reading minds.
The first analog commercially successful TVs come out about 1939.
In the US analog TV broadcasts stopped in 2009, so that's about 70 years that analog TVs were produced. What "vintage" is depends on ones definition, a lot of times on Craig's list anything before 2009 is vintage!
Tube set production ended approximately in 1970, that's about where I would draw the line. However some would put it earlier.
Tubular caps progressed through the years from paper dielectric (many times soaked with oil) in a cardboard tube sealed with wax to paper dielectric in a molded plastic case, to paper plus plastic film in a plastic molded or epoxy dipped case, to film alone in a dipped epoxy case, etc. Problems arise because the paper will degrade, molded plastic cases crack and expose the insides to the environment. Probably other things happened also. Some capacitors in the mid 60's may have still used paper.
So if your TV was made in the late 60s some of the tubulars are OK, it depends on the construction.
Electrolytics before 1980 I would replace.

It is usually customary to state more specifically what you are working on (model) and generally make each thread about that item.
Some of us here online are a bit rusty reading minds.
The first analog commercially successful TVs come out about 1939.
In the US analog TV broadcasts stopped in 2009, so that's about 70 years that analog TVs were produced. What "vintage" is depends on ones definition, a lot of times on Craig's list anything before 2009 is vintage!
Tube set production ended approximately in 1970, that's about where I would draw the line. However some would put it earlier.
Tubular caps progressed through the years from paper dielectric (many times soaked with oil) in a cardboard tube sealed with wax to paper dielectric in a molded plastic case, to paper plus plastic film in a plastic molded or epoxy dipped case, to film alone in a dipped epoxy case, etc. Problems arise because the paper will degrade, molded plastic cases crack and expose the insides to the environment. Probably other things happened also. Some capacitors in the mid 60's may have still used paper.
So if your TV was made in the late 60s some of the tubulars are OK, it depends on the construction.
Electrolytics before 1980 I would replace.

This TV is a 1971 Zenith Chassis 14b38. Definitely a tube set. There are absolutely no viable newly manufactured can capacitors for sale that will work so I have decided to go the 'restuffing' route.

Tube set production ended approximately in 1970, that's about where I
So if your TV was made in the late 60s some of the tubulars are OK, it depends on the construction.
Electrolytics before 1980 I would replace.

You're a bit off. 1975 was the year that most of the major brands killed their last tube/SS hybrid chassis. The GE Portacolor (lasting as a production tube product till at least 1978) being the major exception (along with some small/foreign made names). If you are arguing from an ALL tube (no tube SS/hybrids) standpoint then you're probably late...Hybrids depending on how you define them date from the beginning of the category of PN junction you classify as SS to at least the late 70's.

I have some ~1964 Zenith sets still going fine on their original tubular caps...Shotgun recapping tends to be frivolous in sets past 1965...At that point, it is better to troubleshoot the problem.

I was speaking in general approximate dates for the most part. I didn't want to get bogged down in exceptions and what different manufactures did at different times. I know one of the earliest solid state TVs came out in 1959, Philco Safari, but that's an exception.

So the fact that I am missing this wire, and there is nothing subbed in as Zeno suggested, should I just run some wire and connect to the new can I will be rebuilding? Picture shows from the Sam's how it should be, running from the area where the horizontal hold control is to 1 of the terminals for the larger electrolytic. My situation is that there is currently no connection, no wire, nothing, just empty terminal. What is the consequence of this, just no horizontal hold function? I'm not sure why it would be set up like this.

Often times back in the day a tech would replace one section of a can (when just that section died) by disconnecting the wire to that section's positive terminal, deleting the wire and adding a new cap on the far end of the deleted wire. Look at the hold control (and any points connected directly to it by wire) odds are a newer replacement cap was connected elsewhere by a repair tech.


If the blank terminal appears to never had solder added to it then maybe it was not connected due to a production change or factory wiring error (yes I've seen Zeniths with factory wiring errors). But if a wire was soldered on and removed then my first paragraph is the likely scenario.

Without the schematic, it is hard to definitely say what lack of that cap would do. A lytic is normally for filtering not RC frequency setting. Odds are without it there would be more noise in the circuits it is on...Sometimes that leads to major issues sometimes only minor ones...Zenith sets have a reputation among repair techs of being able to do a damn good job of feigning normal operation despite some major component failure that normally would take out other brands.

Often times back in the day a tech would replace one section of a can (when just that section died) by disconnecting the wire to that section's positive terminal, deleting the wire and adding a new cap on the far end of the deleted wire. Look at the hold control (and any points connected directly to it by wire) odds are a newer replacement cap was connected elsewhere by a repair tech.


If the blank terminal appears to never had solder added to it then maybe it was not connected due to a production change or factory wiring error (yes I've seen Zeniths with factory wiring errors). But if a wire was soldered on and removed then my first paragraph is the likely scenario.

Without the schematic, it is hard to definitely say what lack of that cap would do. A lytic is normally for filtering not RC frequency setting. Odds are without it there would be more noise in the circuits it is on...Sometimes that leads to major issues sometimes only minor ones...Zenith sets have a reputation among repair techs of being able to do a damn good job of feigning normal operation despite some major component failure that normally would take out other brands.

OK thanks for the advice. When I open up the back again soon after rebuilding the cans I will take a look.

See if the old cap is original. If it is or its an OEM replacement
it will have 22-#### on it. Also a 4 number date code & 3 number
EIA code sometimes run together. See if the 22-#### matches
Sams. There may be a production change also BUT I did a lot
of cans on these, enuf to stock them & dont remember one.

73 Zeno:smoke:
LFOD !

See if the old cap is original. If it is or its an OEM replacement
it will have 22-#### on it. Also a 4 number date code & 3 number
EIA code sometimes run together. See if the 22-#### matches
Sams. There may be a production change also BUT I did a lot
of cans on these, enuf to stock them & dont remember one.

73 Zeno:smoke:
LFOD !

I will check this out when I open it back up. I bought a replacement NOS can before I decided against chancing it with dried electrolytes. So when I rebuild the can and open the set back up to install it I will check what you said, take some pictures to post here as well because I will want to rectify any potential mistakes and that seems like a potential problem.

Incidentally where do you guys pick up your hook up wire? Seems like a dumb thing to ask but I am looking around for some 20 awg, solid, 600v, high heat, and with good insulation. Maybe it's hard for me to find because I don't need 100ft or more I'm looking for something inexpensive. I need it to rebuild the cans and so even a 25ft spool is overkill.

Incidentally where do you guys pick up your hook up wire? Seems like a dumb thing to ask but I am looking around for some 20 awg, solid, 600v, high heat, and with good insulation. Maybe it's hard for me to find because I don't need 100ft or more I'm looking for something inexpensive. I need it to rebuild the cans and so even a 25ft spool is overkill.

Your probably going to have get at least 25 ft.
Are you sure you want solid? Stranded can be used more places, like where some movement is expected.

Your probably going to have get at least 25 ft.
Are you sure you want solid? Stranded can be used more places, like where some movement is expected.

I'm not sure about anything, I'm literally an absolute beginner. I'm just following the instructions below and trying to get my set working again after over 2 years.

Does this look remotely correct?

https://www.tubesandmore.com/products/wire-20-awg-solid-core-lacquered-cloth-cover-600v

Luckily I have been reading here and studying a lot. I am glad I figured out about Kester solder before I used the lead-free stuff I bought from Harbor Freight.

Capacitors arrived today from Mouser, once I prepare the new can I will try to power up.

Oh, I see what you are doing now.
I was thinking you wanted it for chassis wiring.
For the capacitor re-stuff I would use bare solid wire, if the leads on the caps aren't long enough. Then, where needed, use heat shrink tubing for insulation.
To get the bare solid you could just remove the insulation from any solid wire. Use could also buy bare wire, often called buss wire. Cloth covered wire wasn't used much in a set as late as yours. Plastic covered wire is cheaper also.
Solid wire is OK for going point to point on the chassis, like from one tube socket to another or a terminal strip. Stranded should be used for thing like CRT sockets, separate speakers and separate tuners. Stranded would be OK for point to point also, that makes it more versatile. Solid is slightly cheaper and is easier to get into a terminal hole so the manufacturer used it for point to point.

I've bought wire from All Electronics. Modern wire usually doesn't have to be rated for 600V like tube electronics often does.
https://www.allelectronics.com/category/825/wire/cable/1.html

I've bought wire from All Electronics. Modern wire usually doesn't have to be rated for 600V like tube electronics often does.
https://www.allelectronics.com/category/825/wire/cable/1.html

Thanks for taking the time to explain that. I understand what I need now. That's exactly what I was hoping to read. Now I just need to order it and then get to work on the rebuild. Can't wait. Thanks again.

I finally got around to tackling this project. I simply cut out all the old electrolytics and soldered in the new ones. My beginner soldering job was kind of sloppy but apparently good enough for the electricity to pass through. I didn't even bother to rebuild the can. I was originally under the impression I would be cutting out ALL the capacitors which is why I found it so daunting. I was under the idea that film capacitors should be replaced. Set has been on for about 2 hours, no problems. During the first 20 minutes picture was occasionally jumpy. I guess it either wasn't warmed up or the settings weren't adjusted properly. This is a 1971 Zenith. Speaker is starting to get tinny, don't know where to go for that problem.

Looking good!

Looking good!

Thanks so much!

I have about 5 consoles waiting to get started on. Would the electrolytic replacement procedure be the same on those or should I get more practice with table tops before moving on to the consoles? I've got two 13" Zeniths I can do next as well.

At the shop we used the wire from a junked Zenith ! Most of it was
braided & tinned, rubber coated followed by color coded cloth. They
WAY over did it ! No one else used has high a quality hook up wire
that I remember. Most used solid wire & it easily broke off over the
years from heat or getting nicked by dykes.

73 Zeno:smoke:
LFOD !

Incidentally where do you guys pick up your hook up wire? Seems like a dumb thing to ask but I am looking around for some 20 awg, solid, 600v, high heat, and with good insulation. Maybe it's hard for me to find because I don't need 100ft or more I'm looking for something inexpensive. I need it to rebuild the cans and so even a 25ft spool is overkill.

I finally got around to tackling this project. I simply cut out all the old electrolytics and soldered in the new ones. My beginner soldering job was kind of sloppy but apparently good enough for the electricity to pass through. I didn't even bother to rebuild the can. I was originally under the impression I would be cutting out ALL the capacitors which is why I found it so daunting. I was under the idea that film capacitors should be replaced. Set has been on for about 2 hours, no problems. During the first 20 minutes picture was occasionally jumpy. I guess it either wasn't warmed up or the settings weren't adjusted properly. This is a 1971 Zenith. Speaker is starting to get tinny, don't know where to go for that problem.
If the bias voltages are good in the audio section, check different fine-tuning settings to see if any improve sound...If none are better tune for best pic then adjust the Buzz control for best sound.

The main difference between console and portable Zeniths is that the consoles have bigger chassis with more parts and room to work.

No lets start a food fight:banana:
On most sets from the mid 60's on I would not recap. Best thing to do
is do only what you need to do to get a raster & evaluate the CRT.
After that there are certain caps that should go. Can caps are often
bad. Most will run hot or be leaking mung out the bottom if bad.
When you get to early solid state sets cans almost never failed.
Example is Zenith CC2 sets. I probably fixed an easy 1000+ of them
and only changed 2 or 3 cans all causing white hum bars due to bad
filtering on the 24 V supply.
Best bet is as you start on your pile post the brand, model & chassis
numbers along with a nudie of the chassis. That way you can be forewarned
of any special care needed when you restart it for the 1st time.
Changing cans in consoles is no different. With Zenith sets from abt
1975 on the chassii were almost the same from 13" - 25". If your 13"
sets are solid states they have a console chassis stuffed into a small
box but still serviceable !

Enuf fer now
73 Zeno:smoke:
LFOD !


Thanks so much!

I have about 5 consoles waiting to get started on. Would the electrolytic replacement procedure be the same on those or should I get more practice with table tops before moving on to the consoles? I've got two 13" Zeniths I can do next as well.

If the bias voltages are good in the audio section, check different fine-tuning settings to see if any improve sound...If none are better tune for best pic then adjust the Buzz control for best sound.

The main difference between console and portable Zeniths is that the consoles have bigger chassis with more parts and room to work.

OK cool I will definitely check that out. I wasn't sure if the speakers just didn't need to be reconed.

No lets start a food fight:banana:
On most sets from the mid 60's on I would not recap. Best thing to do
is do only what you need to do to get a raster & evaluate the CRT.
After that there are certain caps that should go. Can caps are often
bad. Most will run hot or be leaking mung out the bottom if bad.
When you get to early solid state sets cans almost never failed.
Example is Zenith CC2 sets. I probably fixed an easy 1000+ of them
and only changed 2 or 3 cans all causing white hum bars due to bad
filtering on the 24 V supply.
Best bet is as you start on your pile post the brand, model & chassis
numbers along with a nudie of the chassis. That way you can be forewarned
of any special care needed when you restart it for the 1st time.
Changing cans in consoles is no different. With Zenith sets from abt
1975 on the chassii were almost the same from 13" - 25". If your 13"
sets are solid states they have a console chassis stuffed into a small
box but still serviceable !

Enuf fer now
73 Zeno:smoke:
LFOD !


Thanks for this valuable info. I am going to enjoy the fruits of my labor on this set and then take stock of where I stand for the next projects.

Forget the 13 inchers. Opened it up - zero room to work. These things were meant to be thrown away long before any electrolytics would have dried out and need to be replaced. Will move on to consoles.

Quick question:

I have a mid 60's Zenith rectangular b/w console with incredibly strong CRT. Did what Zeno said, turned on just to get an idea before I start. Picture is twisted. I guess this is a yoke thing.

Does anyone have a link to the procedure for getting the picture to display straight?

Display crosshatch on screen loosen yoke bracket rotate yoke while looking at screen for straightness tighten bracket when straight.... easy peasy lemon squeezy.

10-13" tube Zeniths are VERY SERVICEABLE you just need to figure out how to get them apart and get used to the difference in layout...compare one to a cheap GE or 5 and you'll appreciate the Zenith.

Fear not the 13" !! I would rather do them all day than anything else.
SO easy & its on the bench instead of getting up & down. As far as the
B&W console goes a better set was NEVER built. They are almost immortal.
The only weak spot on them was the audio could be buzzy & hard to tame.
That was common to most Zenith tube sets.

73 Zeno:smoke:
LFOD !

Display crosshatch on screen loosen yoke bracket rotate yoke while looking at screen for straightness tighten bracket when straight.... easy peasy lemon squeezy.

10-13" tube Zeniths are VERY SERVICEABLE you just need to figure out how to get them apart and get used to the difference in layout...compare one to a cheap GE or 5 and you'll appreciate the Zenith.

OK cool thanks a lot.

Fear not the 13" !! I would rather do them all day than anything else.
SO easy & its on the bench instead of getting up & down. As far as the
B&W console goes a better set was NEVER built. They are almost immortal.
The only weak spot on them was the audio could be buzzy & hard to tame.
That was common to most Zenith tube sets.

73 Zeno:smoke:
LFOD !

There was literally no room to even get tools toward the bottom of the electrolytic to clip the wires but if you guys say it is possible to work on them I will take another look.

There was literally no room to even get tools toward the bottom of the electrolytic to clip the wires but if you guys say it is possible to work on them I will take another look.

I've never seen it hard to do in a Zenith TV. I've seen a lot of Zeniths, but I've not seen everything. Usually, they make it easy in portables assuming you've sufficiently separated cabinet and chassis. Worst cases I've seen in other American sets is you have to remove a thing or two on the chassis to get at a can. If it is stumping you then, by all means, post some pics of the area, and one of us will probably remember a trick or figure it out from looking...We are here to help.

Assuming its a 13GC10 or later HC, JC, KC, LC..........
Remove two 1/4" screws in top corners of chassis. There may also
be also one or two along the sides. Now the chassis will tilt down.
The can is behind on the sub-chassis. MOST were mounted on
a small steel plate held by a 1/4" to the steel sub-chassis. Remove the
bolt & it flips out and its easy to change. If you need more room pull the
four 1/4" under the set & the chassis will come out. Take your time
so you dont damage the CRT board or pull any wires. At that point
everything unplugs if needed. Zenith always put serviceability on top.
The only mistakes I remember were the dial lamps & cans in the
hybrid sets. They actually took a few minutes to change !

73 Zeno:smoke:
LFOD !

Pictures of my two 13" Zenith's coming soon. One of them is purple and appears to have been made overseas. I am guessing this is indicative of the set being made after Zenith's glory days. I would say both sets are mid to late 70's.

Before I get to the 13" sets, as I have been continuing my education here and around the 'net I have begun to second guess my work on the 19".

Questions 1 & 2

1) Since rebuilding the cans turned out to be too laborious and annoying (and I don't give a damn what it looks like inside) I simply clipped the wires and soldered the new electrolytics in below. Now here is the thing. For the negative grounding - I simply soldered that lead to wherever was an available metal space on the chassis. Given that this is a (I think) a hot chassis design - is that OK? As far as shorting out or any other dangers? I think I have heard members here refer to my set as transformer less/ hot chassis and I have been reading some horror stories so I thought I'd better ask.

2) The insulation on the filter choke is iffy. It is cracking and splitting apart. Can I just join it back up with electrical tape or leave it alone?

OK, thanks again for helping a real NOVICE

1.) Were these bare metal cans with the outer metal shell attached directly to the chassis? If yes then all chassis ground points should be valid negative terminals for the new caps. If no then I assume the originals had a cardboard sleeve and the 3-4 negative mounting ears did not connect to chassis but instead connected to an insulating wafer that is riveted to the chassis in two places...Those have a separate negative lead (or several if used as a terminal strip for the neg bus) going to their outside terminal(s)...You MUST connect the new caps' negative leads to the SAME negative bus wire as their can is on.

Some sets only chassis grounded their caps, some only used the floating negative bus, some did both, some had the negatives on different caps on different busses...It depended on how complex the power supply was. Make sure the replacements negatives are on the same negative as the originals.

2.) sometimes the outer paper/cellophane/plastic layer peels. If the winding has not shorted or shorted to the core all should be fine...Albeit less pretty. Look it over maybe ohm it out...If it is fishy you should notice.

Stress a bit, but not too much. We all goof up something, often in the power supply, at least once...Having a variac helps reduce damage risk on first power up.

1.) Were these bare metal cans with the outer metal shell attached directly to the chassis? If yes then all chassis ground points should be valid negative terminals for the new caps. If no then I assume the originals had a cardboard sleeve and the 3-4 negative mounting ears did not connect to chassis but instead connected to an insulating wafer that is riveted to the chassis in two places...Those have a separate negative lead (or several if used as a terminal strip for the neg bus) going to their outside terminal(s)...You MUST connect the new caps' negative leads to the SAME negative bus wire as their can is on.

Some sets only chassis grounded their caps, some only used the floating negative bus, some did both, some had the negatives on different caps on different busses...It depended on how complex the power supply was. Make sure the replacements negatives are on the same negative as the originals.

2.) sometimes the outer paper/cellophane/plastic layer peels. If the winding has not shorted or shorted to the core all should be fine...Albeit less pretty. Look it over maybe ohm it out...If it is fishy you should notice.

Stress a bit, but not too much. We all goof up something, often in the power supply, at least once...Having a variac helps reduce damage risk on first power up.

Thank you for your reply and valuable knowledge. Please see attached pictures. I green check marked the type of capacitors my set has. I am guessing by the information you provided I am in the clear. That is very reassuring.

Those are the two types I was describing. It sure looks like your in the clear. Good luck.

I've been known on sets where the can area is cramped and the negative is chassis (or the negative line is convenient) to move the new lytic elsewhere on the positive line to a place with more room like what you describe...What you are doing is a valid and logical layout change.

Those are the two types I was describing. It sure looks like your in the clear. Good luck.

I've been known on sets where the can area is cramped and the negative is chassis (or the negative line is convenient) to move the new lytic elsewhere on the positive line to a place with more room like what you describe...What you are doing is a valid and logical layout change.

Thanks man, that's great to hear. I think I will fire the set back up then.

I just want to bring this thread back up for a second. Someone earlier mentioned arcing and the gunk on the crt near the hv connector. I did skip this step but I think it would be good to clean due to some obvious symptoms. I do remember I had a tough time cleaning it. Any tips as far as cleaners or techniques or do I just use a dry cloth and muscle it off? It may sound silly but I couldn't clean it well last time the back of the set was off.

Rubbing alcohol is my favorite for the area around the NV connection on the crt, follow up with glass cleaner for a good shine. Remember there is a black aquadag coating as close as 2" to the HV connection. The dag needs to be there the dirt not so much...Telling them apart takes experience.

Rubbing alcohol is my favorite for the area around the NV connection on the crt, follow up with glass cleaner for a good shine. Remember there is a black aquadag coating as close as 2" to the HV connection. The dag needs to be there the dirt not so much...Telling them apart takes experience.

rubbing alcohol works for me. There is about a 1"by2" area missing DAG, I put a piece of electrical tape over it. DAG seems expensive. Do I need to buy some just to coat this small area? The reason I am cleaning the gunk near the HV is the occasional pops and hisses which I guess is the arkover.

rubbing alcohol works for me. There is about a 1"by2" area missing DAG, I put a piece of electrical tape over it. DAG seems expensive. Do I need to buy some just to coat this small area? The reason I am cleaning the gunk near the HV is the occasional pops and hisses which I guess is the arkover.

A picture would help... blind advice is don't put any day closer than 1.5" to the HV connection, and any piece smaller than a dollar missing is okay as long as there are no islands. All dag must connect to all other dag any unconnected islands must be connected with a conductor (ideally another layer of dag) or removed... islands arc to each other and that is very bad.

Slip Plate was under 15$ on wallmarts website last I checked...it makes a great dag substitute.

rubbing alcohol works for me. There is about a 1"by2" area missing DAG, I put a piece of electrical tape over it. DAG seems expensive. Do I need to buy some just to coat this small area? The reason I am cleaning the gunk near the HV is the occasional pops and hisses which I guess is the arkover.

The tape wouldn't help anything and of course if you remove it you will probably pull up more dag. The snapping could be coming from other places besides the CRT. Turn the lights out and look around the flyback and HV rectifier.

thanks guys. I finally have a few minutes today. I think I'm going to get back in there for a bit today and take care of a few things. appreciate the advice.

Quick ?

I get programming to my sets via the following chain:

Dvd player-macrovision remover thing-rf modulator-coaxial converter.

So the signal makes a long, strange trip.

In short, the set runs great, but the audio is full of hum/noise/interference whatever you want to call it.

Is there a remedy for this or is it par for the course given the set up?

Thanks in advance

If the picture is OK, no reason why the audio should be bad with your setup. Have you tried another TV?

The exact set and modulator can have an effect on audio quality. If the modulator is one of those consumer-grade models some of those modulate the video over %100 (which generates PM/FM noise based on video content) and later FM modulate the same carrier (adding sound to the noise)...

Some sets like Zeniths had a Buzz control that needed to be set correctly or the sound would be poor.

Knowing the exact type of noise in the audio and more specifics would help in diagnosis.

The modulators I have are from best buy and radio shack. The noise is just a background, persistent buzz. It is reduced when I switch to channel 4 on the set and modulator. The noise level varies based on what is shown on screen. DVD menus with or w/o music tend to produce the loudest noise. Once the show gets going the noise/buzz is more steady but can vary based on dialogue/music/silence on screen. I notice the noise varies when I manipulate the connection (anything to do with silver w/ gold plating on the video cables?). Anyway, it's an annoying problem. No other sets to try it on.

The best thing to do with an intermittent cable is to trash it. You will spend much more $$ worth of your time trying to find out exactly what is wrong with it than buying a new one, and then most likely have to trash it anyway. Do this first before trying any other fixes.

Beyond that, read Electronic M's comments on modulators and also the buzz control that some sets have.

Thanks guys.

Pulled up the Sam's for my set. Located buzz control. Looks like I will have to take back of set off again. Doesn't say how to adjust. Turn it clockwise or counter clockwise?

Upon further research I see "buzz" in rf modulator is a big issue. No definitive solution.

Will fiddle w/ buzz thing-a-ma-jig tomorrow.

Turn the buzz control back and forth until you find the minimum buzz setting.

Turn the buzz control back and forth until you find the minimum buzz setting.

+1

Also regarding modulators, get a Blonder Tongue AM40, AM60 (if you want to transmit wirelessly), or BAVMz (get one that is set to a channel you want that is unused by local DTV) those are professional (cable co grade) equipment with manual modulation control provisions and will allow you to set them to NOT send buzz. They may need a few new lytics but are excellent after that when set up properly.

Zeniths one fault in the tube days was audio buzz. Some
sets you just couldnt tame completely. One last thing to
check is be sure the AGC is not set too high. The detector coil
could be touched up also but its best to leave that be.

73 Zeno:smoke:
LFOD !

Thanks everyone. Adjusted Buzz control. Marginal to decent improvement. At this point, ANY improvement is a win.

Zeno, you're breaking my heart. Just put the back on for the 32nd time in three days. I saw the ACG before I put it back on the last time, asked myself, "Gee, wonder what that does?"

If this is worth adjusting I would open it back up. What do I do, just turn it left/right while observing picture/sound?

Thanks again everyone, this site is so helpful (especially to someone just getting started).

AGC will have a particular adjustment routine in the service manual.

Generally, setting too low causes low contrast weak picture and even loss of sync, while setting it too high can cause overload and loss of sync (picture breakup). It may be possible to set it high for super contrast without breakup, but then have the picture break up when you change channels.

For my RCA CTC-5, they tell you to adjust upward until breakup, then back off to get a picture, then switch to a blank channel and back; if it breaks up again, reduce the setting some more.

The laboratory procedure for any set would be to adjust for a specified known video detector output level with a scope on a test pattern.

Don't know the recommended procedure for your set, but if you don't have it you can try the breakup-restore procedure. You may very well find that setting it wrong increases the buzz too.

AGC will have a particular adjustment routine in the service manual.

Generally, setting too low causes low contrast weak picture and even loss of sync, while setting it too high can cause overload and loss of sync (picture breakup). It may be possible to set it high for super contrast without breakup, but then have the picture break up when you change channels.

For my RCA CTC-5, they tell you to adjust upward until breakup, then back off to get a picture, then switch to a blank channel and back; if it breaks up again, reduce the setting some more.

The laboratory procedure for any set would be to adjust for a specified known video detector output level with a scope on a test pattern.

Don't know the recommended procedure for your set, but if you don't have it you can try the breakup-restore procedure. You may very well find that setting it wrong increases the buzz too.

Thank you. I will be getting back in there soon. Will check that out!

Another day, another problem.

So this set has been working so great, on for about 30 hours without any problem whatsoever.

A couple of days ago I was faced with a novel problem. The power and volume knob popped off and the plastic lever was seemingly too short to get it back on. Anyway, I did get that back on, unfortunately with the aid of super glue. I did have to pull the plastic lever out a bit too.

While I had it opened up I said let me fool with the ACG so that this could be hopefully the LAST time I have to open it up (at least for a while).

I am not sure what happened but I set it up in a place so I could fool with the buzz control and ACG. Then, it suddenly would not turn on. I mean it turns on, all the tubes light up w/ the exception of the HV rectifier tube. No raster.

Any ideas? Did I short something out? Did it have to do with the fiddling of the on/off switch? Fuse?

:tears:

If the tubes are lighting but no sound or other signs of life then you lost B+... Probably the main rail off off the rectifier. Figure out where it is dead with voltage checks.

BTW HV rectifiers & focus tube dont light up or
barely glow...........

73 Zeno:smoke:
LFOD !

If the tubes are lighting but no sound or other signs of life then you lost B+... Probably the main rail off off the rectifier. Figure out where it is dead with voltage checks.

OK thanks. I need to pick up a few basic pieces of testing equipment I should already own, then I will get in there again. Here we go again. :banana:

BTW HV rectifiers & focus tube dont light up or
barely glow...........

73 Zeno:smoke:
LFOD !

OK, that makes sense. I was wondering about that and if it could be.

While I'm waiting for the parts and tools needed to fix up the '71 portable I decided to open up the '65 Zenith and get the chassis disconnected. I have 3 questions. Please see pics for reference.

1.) This is my first time dealing with the wafer board style capacitor. Can I still use the nichicon style capacitors? My procedure is to clip from the bottom, not re-stuff. I understand the negative grounding procedure is different.

2.) The HV anode connector thing is not sitting tight against the tube it looks like its missing a metal clip on the other side. Thoughts?

3.) I turned this thing on for 2 minutes, great CRT strength but picture was turned. I understand I need to rotate the yoke. When I opened it up what I was expecting to see was not there. Can you explain to me in laymans terms what I would be doing? There is a wingnut screw on top, am I in the right area?

Thanks in advance.

While I'm waiting for the parts and tools needed to fix up the '71 portable I decided to open up the '65 Zenith and get the chassis disconnected. I have 3 questions. Please see pics for reference.

1.) This is my first time dealing with the wafer board style capacitor. Can I still use the nichicon style capacitors? My procedure is to clip from the bottom, not re-stuff. I understand the negative grounding procedure is different.

2.) The HV anode connector thing is not sitting tight against the tube it looks like its missing a metal clip on the other side. Thoughts?

3.) I turned this thing on for 2 minutes, great CRT strength but picture was turned. I understand I need to rotate the yoke. When I opened it up what I was expecting to see was not there. Can you explain to me in laymans terms what I would be doing? There is a wingnut screw on top, am I in the right area?

Thanks in advance.
First, if the outer can terminals do not connect to chassis ( most cans connected like that have a card board tube that hides the above chassis portion of the can) then ground the new caps to the wires connected to the outer can leads of the original and NOT to chassis. The replacement types should be the same style you use to replace any other lytic.

Second, it looks like one of the fingers of the HV connector rusted off. Go find a cheap or free 1980's-2000's CRT TV and take the whole HV lead from that to use as a replacement... you can also transplant the connector from your new lead to the old one if you want....but keep the new wire just the same, you'll need it some day.

Third, loosen the wing nut and and slide side to side to rotate yoke.

Second, it looks like one of the fingers of the HV connector rusted off. Go find a cheap or free 1980's-2000's CRT TV and take the whole HV lead from that to use as a replacement... you can also transplant the connector from your new lead to the old one if you want....but keep the new wire just the same, you'll need it some day.

As usual, thanks for your expertise.

So on this particular point. I didn't follow the wire on the original so I am not sure if it is self-explanatory to completely swap out the HV leads. Whether or not I just use connector or swap out the wire I may need further help on this, do they just disconnect, am I cutting something??

Whether to swap connector or wire is a judgement call for you to make. If the original wire is damaged or significantly deteriorated it may be best to replace it...if all it needs is a clean you may want to keep it.

It typically solders to the bottom of the HV rect socket... how much of a job it is to swap the whole wire varies from chassis to chassis. Gotta look yours over and assess it to make a decision. Be aware that the solder joint under the HV socket needs to be smooth...any sharp points will encourage arcing and or Corona.

Changing the connector: typically you grab the fingers with needle nose pliers and pull the fingers and lead out from the center of the suction cup and unsolder the fingers from the wire then yank the cup off the wire...the old cup will be crusty and difficult. Most newer cups you find will be the same process ( only you have to do it twice forward and once in reverse for a swap), but there are oddballs out there. When transplanting note how the new part was put on and match the workmanship.

Thanks for the answer. I have been busy but am getting around to fixing my TV's. I am back to the '71 as I study more about the '65 HV cup swap out.

Anyway, this '71 is driving me nuts! I just replaced the fuse and a bunch of other stuff Sam's recommended when there is no raster, no sound.

Now nothing has ever been wrong with this set, then one day the volume and on/off knob fell off and ever since then all hell has broken loose! I had to glue it back in but I thought nothing of this at the time but ever since a couple of days after I did that, I get no picture or sound when turning on this set. But today, I got mad and flicked the on knob with my finger and it turned on. Then I tapped the other side (see pictures, I don't know terminology) and it turned on again.

Also, please see video. What the hell is that? If I rock it, it turns on and off while it is powered on? If I set the set upright it won't power on.

https://www.youtube.com/watch?v=XrJn6KWhzq0

Thoughts?

Contacts may be bad on the switch...Not too rare on electronics of that vintage.

Contacts may be bad on the switch...Not too rare on electronics of that vintage.

Alright, gotta look that up. Thanks a lot. Easily fixable? Procedure?

I'm soldering the new capacitors on the '65 now so they will be done when I attempt the HV cup swap.

Breathing in a lot of lead, very healthy hobby!

Alright, gotta look that up. Thanks a lot. Easily fixable? Procedure?

I'm soldering the new capacitors on the '65 now so they will be done when I attempt the HV cup swap.

Breathing in a lot of lead, very healthy hobby!

I typically just hard wire bridge the switch terminals to the ON position and turn the set off by unplugging it...If I have a similar switch/pot combo I can swap the switch mech from or I'm really lucky and have an identical switch/pot combo on hand I'll fix it properly.

I tend not to use the power switches much on my sets I've worn them out before. Instead, I opt for remote controlled outlets or switched power strips.


Be glad you don't have 40's 50's radios and TV's...You find plenty of asbestos sheets in those then you 'have to get out the cocaine straw' as shango66 puts it.:D BTW: if you handle a yellow-green chassis and get that delicious looking mustardy yellow dust on your hands resist the urge to lick it...That's cadmium which is supposed to be worse than lead.

I typically just hard wire bridge the switch terminals to the ON position and turn the set off by unplugging it...If I have a similar switch/pot combo I can swap the switch mech from or I'm really lucky and have an identical switch/pot combo on hand I'll fix it properly.

I tend not to use the power switches much on my sets I've worn them out before. Instead, I opt for remote controlled outlets or switched power strips.


Be glad you don't have 40's 50's radios and TV's...You find plenty of asbestos sheets in those then you 'have to get out the cocaine straw' as shango66 puts it.:D BTW: if you handle a yellow-green chassis and get that delicious looking mustardy yellow dust on your hands resist the urge to lick it...That's cadmium which is supposed to be worse than lead.

Man that's crazy, lol. Yeah I am going to have to study or look for instructions for that contact switch problem. Such a shame, the set works flawlessly besides that.

PS, I'm dealing with resistors this time around. I'm new to them. Please see pic, are those orange bands or yellow? They looked orange before I took the picture, now they show yellow. I threw it out and can't check. I'm not digging this band system, why don't they just write the value on it? PS, are resistors like capacitors where increasing the values are OK? I want to be safe here since I can't determine the exact values.

What light are you using to view the bands? I have noticed that some of my LED flashlights distort color perception quite a bit. Especially ones whose color temperature is pretty white, and ones that are real bright.

Probably yellow. Orange tends to be a lot closer to red on most resistors. Find it on the schematic and double check the value.

Resistance needs to be within tolerance. The silver band indicates that that part should be no more than 10% away from it's labeled value. Wattage is fine to increase on resistors. Resistors tend to increase in resistance when they fail or age really badly...What it will do the circuit if it is substantially over rated value varies (usually it will not cause damage to other parts) depending on where and how it is used...It could be unnoticeable, or it could change a deflection time constant and make a hold control never lock...Worst case is probably if you increased a value in such a way that you lost the drive to the H output tube.

Caution: the color is NOT yellow, it is orange.
Your camera flash and slight overexposure have turned orange yellowish.

It must be orange because orange orange brown silver is a standard value:
330 ohms 10% tolerance.
Yellow yellow brown silver would be 440 ohms 10%, which is not at all a standard value.

Resistors cannot be substituted with any higher resistance value. The substitute should be within the tolerance specified by the 4th band. For example, you could use 330 ohm 5% in place of 330 ohm 10%.

A resistor of a higher wattage may be substituted, that is you could replace a half watt by a one watt of the same resistance and tolerance.

standard values:
https://ecee.colorado.edu/~mcclurel/resistorsandcaps.pdf

thanks everyone!!

PS, just checked schematic, old tv nut was correct.

Thanks for the answer. I have been busy but am getting around to fixing my TV's. I am back to the '71 as I study more about the '65 HV cup swap out.

Anyway, this '71 is driving me nuts! I just replaced the fuse and a bunch of other stuff Sam's recommended when there is no raster, no sound.

Now nothing has ever been wrong with this set, then one day the volume and on/off knob fell off and ever since then all hell has broken loose! I had to glue it back in but I thought nothing of this at the time but ever since a couple of days after I did that, I get no picture or sound when turning on this set. But today, I got mad and flicked the on knob with my finger and it turned on. Then I tapped the other side (see pictures, I don't know terminology) and it turned on again.

Also, please see video. What the hell is that? If I rock it, it turns on and off while it is powered on? If I set the set upright it won't power on.

https://www.youtube.com/watch?v=XrJn6KWhzq0

Thoughts?

Can we revisit this? I tried everything. Can someone give me more information on either the contacts/switches being bad and how to troubleshoot that, or how to wire it to always be on (and turn it on/off via plugging it in or out). I tried everything at my disposal and cannot lick this problem.

Thanks.

Just solder a jumper (wire) across the switch to make it be 'on' permanently.

But from the video, it looks like the break may be in the cord or the safety interlock.

^^^ Yes. Before assuming it's the on-off switch, try holding the chassis steady so the set is on and flex the power cord to see if that's the problem. If it's not the cord/connection then proceed to check / bypass the on-off switch.

The problem is in the power cord/safety interlock. I can tilt tv to the right nothing happens, tilt to the left it shuts off. Wiggle cord it goes on or off. Anyone feeling generous enough to provide lay person instructions to fix this? It would be nice to get this set back on playing Columbo again.

With the set unplugged you can also chase that power wiring problem with a DMM....If you have a DMM with beep mode on continuity and aligator clip leads you can hook it across a suspected intermitent wire/connection/switch/etc. and flex said suspected part and look for the beep of life to stop.

Since you posted while I was writing more info: If you have a spare cord you can try swapping it. You can also do a continuity check on the cord with a DMM. It is possible the cord is fine and the interlock bad, but cord problems are more common. If either cord or interlock is bad you will have to get a replacement for what is bad. There are ways to kludge normal cords on and defeat the interlock, but that is a really crappy way to do it (something to do only as a temporary solution while you hunt the right parts).

Thanks guys. OK, definitely not the cord, tried a few different ones. I don't understand what's happening when I lift the set up and down to make it go on and off. I will have to keep searching.

You might have a cold solder joint somewhere on the chassis. You could with a magnifier have a look at solder connections and look for really small cracks at any connection points. You are probably making connection when turning. You could also look at the solder connections on the switch itself and see if they look alright.

The on/off switch on these just have 2 wires going to the rear
of the on/off/vc you can hook the two wires together & prove
the switch good or bad.

Now look at how the main chassis is built. Terminal strips soldered
onto the steel chassis.
The ends are soldered, sometimes they are soldered along the strip &
and at most tube sockets.
Those are used as common ground often. They do loosen up
especially on certain chassis & cause int problems. This chassis wasnt
known for it BUT it can happen. If you probe at them with a screw driver
& they show a break resolder them.

BTW this set has a simple SPST switch. Many others had gang switches
with as many as 4 switches & 2 pots. Maggy & Admiral come to mind.
Sometimes the switches were NO & NC. "Jumping" them out can
get much more complex.

73 Zeno:smoke:

Thanks everyone for the help. Well, guys I don't know what to say. I tried everything. I was most excited about the cold solder joint theory as my soldering is sloppy and it made the most sense. It almost paid off, but then it didn't. I might just put this set on the backburner until I can meet some people who can help me in real life. For now, the '65 is more promising to work on.

Nothing to do with the world shut down, resurrecting old thread.

1971 Zenith B/W 19inch - I recapped it as my first project and it was working flawlessly for hours on end. Later on, the on/off/volume switch became loose and the 'stick' which inserted into the switch fell out. I glued it back in but ever since then the set doesn't work for some unknown reason. I have no idea if that is related to my problem or a coincidence. The fact that I turn the switch on and the tubes light up, does this mean the on/off switch is not the problem?

Where I'm at this morning - I opened it back up. Plugging it in and turning it on lights up the tubes but I get no sound or picture. It seems like electricity or voltage isn't even running through the thing. Not sure where to start.

I know some people get annoyed with beginners and some people like helping beginners, but yeah, I need help! I gotta get this thing going again! I'm gonna go bust out my old repair books and search this forum but if anyone is feeling charitable and wants to help please let me know.

Thanks!

On this set if the tubes are lit but its dead the switch is OK.
Look at the ground posts like mentioned in my prev post.
Also get a long plastic stick & lightly push on things to narrow down the area
the problem is in.
After that you will need a schematic & meter but it should be easy to find.
good luck
Zeno:smoke:
LFOD !

On this set if the tubes are lit but its dead the switch is OK.
Look at the ground posts like mentioned in my prev post.
Also get a long plastic stick & lightly push on things to narrow down the area
the problem is in.
After that you will need a schematic & meter but it should be easy to find.
good luck
Zeno:smoke:
LFOD !

Hold the phone. I think I licked it. What happened was this was a case of bad soldering. The problem was that one of the wires came loose. I couldn't see it due to the electrical tape. That's why if you watch the video I posted earlier in the thread it shut on and off as I rocked the set, as the wire was touching and then untouching. Well, I guess I learned a valuable lesson.

It works now but I'm getting extremely loud buzz/hum/interference. Something like that. any tips for that? Buzz control does nothing.

The buzz control is only useful when you have a good signal received.
Please don't use tape, it never lasts and can get messy. Check out heat shrink tubing, it takes a little planning because you have to put it on before you finish soldering.
Recheck you connections.

Thanks, everyone.

When the TV is plugged in alone the snow sound is normal.

When I have the DVD player, RF Modulator and Digital Video Stablizer plugged in it creates the buzzing. I have tried different outlets, unplugging nearby things not needed, nothing. Am I getting some kind of interference by having this setup near my other electronics?

Sucks to get this close and now have such a dumb problem.

Buzz can be a PIA on tube type Zeniths.
Try turning down the AGC control. Its along the back like the buzz control.
If its too high the set will buzz, too low & the pix will wash out.

Next problem is sources. These sets are before any add ons like games,
VCR, DVD, cable boxes etc so often they buzz or get torn up pictures.
Best test is usually a VCR direct to ch 3. The pix will tear at the top
but the buzz will be much less if at all if the TV is normal.

73 Zeno:smoke:
LFOD !

Buzz can be a PIA on tube type Zeniths.
Try turning down the AGC control. Its along the back like the buzz control.
If its too high the set will buzz, too low & the pix will wash out.

Next problem is sources. These sets are before any add ons like games,
VCR, DVD, cable boxes etc so often they buzz or get torn up pictures.
Best test is usually a VCR direct to ch 3. The pix will tear at the top
but the buzz will be much less if at all if the TV is normal.

73 Zeno:smoke:
LFOD !

Thanks, Zeno. I hear ya, I'll try that. 2 years ago I had this thing playing Columbo from a DVD player with no buzz. I will try to fiddle again with the AGC and whatnot. The sound I am getting is like a ground loop type thing.

Buzzing is loud and won't go away. Stays the same pretty much if you lower or raise the volume.

Tried>
Adjusting AGC every which way
adjusting Buzz Control
adjusting contrast
switching outlets
moving equipment
different cables
different source material and players

I guess now I will have to open it back up. Is this a bad tube? Which tube would be most likely? I don't have testing equipment.

If anyone has anything else I can try please let me know.

Buzzing is loud and won't go away. Stays the same pretty much if you lower or raise the volume.
Could it be described more as a "hum" than a buzz? Since it remains the same irrespective of vol control setting, it would be 'downstream' (in the signal chain) from the vol control. Shorted output tube maybe(?). See if tapping the tube has any effect on it.

Have you tried using a good 90s or newer set to check your signal source?

Could it be described more as a "hum" than a buzz? Since it remains the same irrespective of vol control setting, it would be 'downstream' (in the signal chain) from the vol control. Shorted output tube maybe(?). See if tapping the tube has any effect on it.

It sounds exactly like this noise coming from an unrelated video I just watched:
https://youtu.be/CmEyYAjjsn0?t=429

Very loud, disturbing buzzing. Last time the set was on 2 years ago there was no buzzing like this.

I think the RF Modulator has something to do with this but I am apprehensive to order a new one and then be out the money if it doesn't help. I was hopeful when I read I should unplug one audio cable as the set is likely monaural but that didn't help. The buzz is coming in right through the video cable. Picture is perfect and enjoyable.

I will open it soon and try to tinker but I am at a loss. I appreciate anyone who can help me overcome this.

Thanks!

Have you tried using a good 90s or newer set to check your signal source?

Yes I did and everything was fine with it.

It sounds exactly like this noise coming from an unrelated video I just watched:
https://youtu.be/CmEyYAjjsn0?t=429

Very loud, disturbing buzzing.

But you say the buzz is the same irrespective of volume control setting :saywhat:

But you say the buzz is the same irrespective of volume control setting :saywhat:

Yes, sir.

Could it be described more as a "hum" than a buzz? Since it remains the same irrespective of vol control setting, it would be 'downstream' (in the signal chain) from the vol control. Shorted output tube maybe(?). See if tapping the tube has any effect on it.

+1
Another possibility is some open or bad connection in the audio path between the volume control and the output tube (or a bad filter cap)..... If there's an open in the audio chain where there is some capacitive pick up of the sound but strong(er?) Capacitive pick up of hum from literally anything running 60Hz that could do it.

Another possibility is some open or bad connection in the audio path between the volume control and the output tube (or a bad filter cap).....
Also, if the resistance element in the vol control were open at the ground end, it would cause the control to have little or no effect (granted, this is a long shot and highly unlikely).

Assuming the vol control is good and operating correctly, then the buzz has gotta be getting in downstream of the control.

Al, just for the heck of it, roll the vert hold fully stop-to-stop while listening to the buzz. Does the buzz change pitch (frequency) as you turn the control? If not, that eliminates vertical sweep as the problem source.

Al, just for the heck of it, roll the vert hold fully stop-to-stop while listening to the buzz. Does the buzz change pitch (frequency) as you turn the control? If not, that eliminates vertical sweep as the problem source.

No, it does not, the buzz stays the same while rotating the vertical hold.

I haven't had a chance to open this set back up to try the other suggestions but will try to soon and report back.

Thanks, everyone for pitching in. I just need to solve this problem ASAP, lol.

Opened her up. Tinkered. Wouldn't you know it? This BUZZING was due to...drumroll...

Another case of my BAD, SLOPPY soldering. Basically, some of my soldering came undone and the wires weren't touching the chassis anymore where they needed to be. Re-did them and the buzzing is gone.

I guess let this thread live on as a cautionary tale to other beginners.

Thanks, everyone for the help!

PS...Buzzing is gone but my next challenge is to properly set ACG, buzz control, and then get a nice setting on contrast and brightness. I guess that part will be trail and error.

Glad you got it fixed.

One thing I have found very beneficial is to have a BIG 75W or higher soldering IRON. Getting any chassis ground or especially large solder joint to melt and flow with a smaller iron is at best very slow and often doesn't give good joints. You can make a small iron work (God knows I did for more than a decade) but once you have a big one at your disposal you'll want it for everything but some of the tighter/finer work.

Glad you got it fixed.

One thing I have found very beneficial is to have a BIG 75W or higher soldering IRON. Getting any chassis ground or especially large solder joint to melt and flow with a smaller iron is at best very slow and often doesn't give good joints. You can make a small iron work (God knows I did for more than a decade) but once you have a big one at your disposal you'll want it for everything but some of the tighter/finer work.

That's good advice because I have a small dinky iron from Harbor Freight.

What does it mean when there is a sudden 'wind' sound coming through the set? I don't know if the term wind is good but it reminds me of the sound on an old camcorder taping on a loud, windy day. Anyway, it is like a sudden scratchy sound. It comes and goes, sometimes touching the set or the knobs induces the sound. Most of the problems I have had on this set have been to my horrible soldering.

Sounds like an intermittent connection. Could be from a dirty pot or tube socket contact, dirty tuner, intermittent short in a tube or cold solder joint...to track it down with the set running take a small wood or plastic dowel and tap around various parts of the set and find the spot that does it with the faintest tapping...the problem will be physically close to that spot.

Thanks friend. I will check out that the next time I open her up. Appreciate the lead.