View Full Version : 1960s Sylvania Color TV: My first all tube color TV
vortalexfan 07-19-2023, 01:11 AM Greetings everyone, I will be picking up tomorrow locally a mid to late 1960s Sylvania Color TV that appears to be from what I can see of the pictures an all tube Color TV or perhaps a hybrid (I'm not sure becuse the pictures I saw of the inside of the unit were kind of limited to a small area of the main chassis where I saw at least two or three tubes in the picture and the convergence board and the picture tube besides a front view and a back view of the unit with the cover on the back.
The person who listed it on facebook marketplace said her husband picked it up at a garage sale several years back with the intention to fix it up but he lost interest in it, she said that when he powered it up it produced sound but no picture which I'm wondering if either the HV Rectifier is dead or maybe they were too impatient to wait for it to produce a picture, especially if it didn't come equipped with the "instant on" feature. One thing I did notice about the TV from the pictures of the inside of the set that I could see, is that it looks to be a low hours set because it has very little dust built up on the picture tube and on the chassis, and the TV appears to have the original Sylvania picture tube in it yet and the cabinet looks darn near mint.
what do you guys think, will this be a good TV when fixed up and what kinds of things should I look out for when trying to restore this set?
Thanks for your help.
See pictures below.
Alex KL-1 07-19-2023, 06:48 AM Congratulations!!
Well, this is a hybrid; in these photos, I can see some transistors in white yellowed sockets.
Even so, is a very interesting piece of it's time: tubes on deflection, all discrete video/IF/RF processing (at least I don't see any IC in it), delta-gun CRT, etc
Anxious to see if CRT and flyback are on a good shape!
Good luck with your restoration!
BTW, is my dream to include a hybrid color TV in my collection, since the first one TV I disassembled in my childhood was a hybrid. All those coloured parts, a lot of coils etc hehe
But I don't had/have luck on finding hybrids here, and these TV's are too heavy to send overseas...
Looks like a good start.
CRT looks original
Run on a variac or dim bulb first, see videos.
If power supply is up find out why no HV FIRST !
DO NOT do a mass recap ! I can give you NO good reasons to do that
but a ton of reasons why not to. Fix the set one stage at a time.
& take your time.
BTW these were decent sets. The main problem was the PCB's were
not good especially around tube sockets.
It also has a chassis number D-08 or something along those lines.
Find that, its the best ref.
73 Zeno:smoke:
LFOD !
Electronic M 07-19-2023, 09:21 AM Based on a sams search of the model and what I have seen of that era of Sylvania it looks like a D12 chassis.
https://www.samswebsite.com/en/photofact/search/index/page/3/samsid/1045_2
The D12 and D16 were the chassis that put Sylvania on the map as a good TV brand. (Prior to that their color sets were mediocre RCA clones, and in house monochrome sets where they stuck a lousy portable chassis in a console cabinet with a halolite gimmick to get customers.) They competed on picture quality with the best early SS and hybrid sets from Zenith and RCA.
I've got a D13 (basically a D12 with provisions for a flying spot slide scanner that it was sold with) and ignoring 2 mouse chewed wires and an audio issue I haven't gotten to yet the TV portion still works great.
These sets are known for some resistors in the color demod going low in value and causing issues.
I agree with Zeno that PCB tube sockets aren't the best on these.
As for HV put a meter on the G1 and G2/screen of the H output. G1 needs to be something like -75V (I'd need to see the Sam's to know) if it's not sufficiently negative troubleshoot the H osc first, it it is sufficiently negative the G2s deviation from the schematic value will tell you if something is open or shorted in the flyback/yoke/boost system. High G2 indicates short, low G2 indicates open. HV rectifiers can fail in anything. If the horizontal seems normal and you can't test or sub the rectifier stick a CFL bulb or a small neon indicator near the flyback donut with the set on. If the bulb glows from the ambient RF then the horizontal is running enough to make HV and either the rectifier is bad, the regulator is lugging HV down (removing the top cap and putting it in a jar is a good test of that) or gun bias on the CRT is preventing screen light.
DavGoodlin 07-19-2023, 10:31 AM Sylvania hybrid and others used to get tin whiskers in the metal covers of grouped potentiometers.
Cleaning them sometimes helped but don't jump on this one until you sort out the other issues. The last D16 I saw (2014) had a shorted deflection yoke and fortunately Moyers Electronics had a NOS one. The VK member who has that set posted a picture recently.
I have this set and can cite examples going back to late 50s when these came out.
https://www.youtube.com/watch?v=ngWMdVjmWQU Also same issues on GE portacolor
vortalexfan 07-19-2023, 05:48 PM Well the set has high voltage and produced a picture, but I am having a hard time getting the tuner to lock in on a signal (digital converter box or DVD Player being ran through an RF Modulator) and when I can get it to lock in on something the vertical won't lock but the horizontal will lock fine.
I checked all of the tubes and they all tested like band new yet except the horizontal output tube which I had to replace with a NOS one because the original one the grid cap broke off when I tried to remove the tube to test it.
This TV thankfully doesn't have the tin whiskers issue, but I have a feeling that the X and Z demod transistors might be bad or shorted because this TV is doing the same thing as the one that Shango worked on where it has plenty of red and Blue but no green or at least not much green anyways, the picture tube seems pretty strong yet other than that.
The X and Z demod Transistors are SE1002s which I'm not sure what those cross-reference to as far as NTE or some other more modern part (this set uses all germanium top-hat and black cap Silicon transistors (the ones that look like
small black gumdrops.)
I was trying to adjust some of the screen adjustments and I accidentally diddled the AGC adjustment (because its near some of the screen adjustments, and now the screen looks weird.
JohnCT 07-20-2023, 08:35 AM I wouldn't run it any further until I verified the carbon resistors that feed the transistor section have not dropped in value. I remember having one about 50 years ago that trashed every transistor and choke coil in the chroma/video section by dumping 2X the voltage into the signal circuits.
John
vortalexfan 07-20-2023, 10:17 AM I wouldn't run it any further until I verified the carbon resistors that feed the transistor section have not dropped in value. I remember having one about 50 years ago that trashed every transistor and choke coil in the chroma/video section by dumping 2X the voltage into the signal circuits.
John
OK, will do, I'll check every resistor in that section of the TV and make sure they haven't drifted up in value. :thmbsp:
old_coot88 07-20-2023, 12:48 PM FWIW (it may not apply in this case), we ran into some Sylvania hybrids that had two 2 watt carbon comp resistors that chronically cook and go 'waay low in value. IIRC they were something like 27K and dropped to a few hunderd ohms. They were the collector load resistors for the two demod transistors, which shorted from overcurrent. Apparently the resistors' phenolic casing charred to carbon over time, shunting the resistive elements.
Edit... those two resistors may have been more like 2.7K, not 27K. Been a lotta years.
FWIW (it may not apply in this case), we ran into some Sylvania hybrids that had two 2 watt carbon comp resistors that chronically cook and go 'waay low in value. IIRC they were something like 27K and dropped to a few hunderd ohms. They were the collector load resistors for the two demod transistors, which shorted from overcurrent. Apparently the resistors' phenolic casing charred to carbon over time, shunting the resistive elements.
Ditto
I only saw it on the portables but first thing to check. Basically it
put 200+ volts on the 24 V line. Things explode !
Rolling may be from the AGC oops. If the tuner is SS there may be 2
controls. IF AGC & RF AGC.
Zeno:smoke:
vortalexfan 07-21-2023, 12:56 AM Ditto
I only saw it on the portables but first thing to check. Basically it
put 200+ volts on the 24 V line. Things explode !
Rolling may be from the AGC oops. If the tuner is SS there may be 2
controls. IF AGC & RF AGC.
Zeno:smoke:
The tuner on this TV is Solid state according to the tube & transistor placement chart on the back of the TV.
The AGC adjustment that I accidentally diddled was the one that was next to the Vertical Linearity and Height Adjustments, which I was trying to adjust those because of the vertical roll that I couldn't lock in, and the AGC flub caused the picture to do some sort of weird thing where the picture looked like a red and blue candycane stripe going down the screen with some other strange screen distortions mixed in.
The 2 watt resistors you were talking about aren't burnt to a crisp or anything in my TV (they actually look like brand new yet) but they do measure a little low (around 10k-15k ohms rather than the 27k ohms that they should measure, but they don't measure in the hundreds of ohms range that you said they would measure if they were truly bad.)
As for trying to measure whether or not the transistors were bad or shorted, I don't have a transistor checker but I do have a DMM with a diode check mode but the transistors are so small and have such small leads that none of my test probes or aligator clip adaptors for my DMM test probes will fit onto the transistor leads without touching each other.
Do you have any suggestions as to a way to test these transistors without either damaging them or having to spend a whole lot of money on an expensive transistor tester?
I know the $5 Harbor Freight Special DMM had a dedicated transistor tester section but I'm not sure how accurate it is as I've never had a chance to use that function on one of those before (I did have one of those $5 Harbor Freight Special DMMs that I picked up NOS at Goodwill once but it broke on me before I had a chance to extensively try out all of the features on it.)
Electronic M 07-21-2023, 09:35 AM If those resistors are truly as low as you are measuring then they are badly out of tolerance and need to go ASAP....That said it's been a while since I've looked at the schematic and there could be a parallel path creating a false reading. In any event if you don't want to be doing tons of cross referencing for replacement transistors that might get damaged, then your next move should be to unsolder a leg of each of those resistors and double check how they measure and IMMEDIATELY change them if they have drifted low and are out of tolerance.
Transistors on old Sylvanias usually plug in to little white
sockets. Just be careful they go back in rite !
Zeno
old_coot88 07-21-2023, 04:57 PM Do you have any suggestions as to a way to test these transistors without either damaging them or having to spend a whole lot of money on an expensive transistor tester?
Dunno how well this test would work with a digital ohm meter, but seems like it should provided the test voltage on the leads is proper polarity. I use a Simpson 260 analog meter set on highest R scale. The transistor needs to be NPN type (which your are) and out of circuit. You must identify which pins are emitter, base and collector, and bend at least two pins just enuff to attach clip leads.
Clip negative lead to emitter, positive to collector. Meter should read open circuit. Now moisten a fingertip and touch between base and collector. Resistance should drop as transistor turns on, indicating gain. (In the rare instance of testing a PNP transistor, just reverse the meter leads.)
old_coot88 07-21-2023, 05:18 PM If those resistors are truly as low as you are measuring then they are badly out of tolerance and need to go ASAP....That said it's been a while since I've looked at the schematic and there could be a parallel path creating a false reading.
Do you happen to remember the + source those two resistors are fed from? Seems like it as a lot higher than 24V, but I could be wrong. Also I could be wrong on the 27K value, but that's the figure that sticks in mind. A schematic would sure be handy.
The resistors looked "different". IIRC they turned color & got a bubbly
coating on them. Lift one end & retest them.
Same with transistors not in sockets. Lift 2 out of 3 leads & test with
DVM on diode test. We had a few transistor checkers & they collected dust.
Only one tech used them & he was playing engineer & wasting time.
Bottom line is parts IN circuit very often read bad.
73 Zeno:smoke:
LFOD !
Electronic M 07-21-2023, 07:39 PM Do you happen to remember the + source those two resistors are fed from? Seems like it as a lot higher than 24V, but I could be wrong. Also I could be wrong on the 27K value, but that's the figure that sticks in mind. A schematic would sure be handy.
Unfortunately no, but 98% chance I have the schematic. I'm hoping to have bench time this weekend, maybe I can dig it up while I'm down there.
vortalexfan 07-22-2023, 12:31 AM I saw that my Sylvania TV is in Sam's 1045-2 which I don't have a physical copy of and I try to avoid buying the PDF copies from them unless I have no choice in the matter because I think its ridiculous to charge $22 for a PDF reproduction of an original service manual that may or may not be of that great of quality compared to the original paper document, and feebay is hit or miss on having original Sam's Photofacts for sale, and some times they want just as much on feebay for an original Paper copy as Sam's does for a PDF reproduction. Which is why if someone on here has an original paper copy that they can scan and upload I prefer to go that route rather than having to pay $22 for a photocopy of an original Sam's, or if I can hold out for someone locally that might have a bunch of old sam's folders that they are liquidating from their collection for a decent price, like what Shango did.
vortalexfan 07-22-2023, 01:00 AM Well, I did suprisingly enough manage to find an original hard copy of Sam's folder #1045 (the whole folder, not just one of the sections out of the folder) for $9 plus shipping.
But I had to search a little bit because there weren't many listings for individual Sam's folders, they were mostly just listing the compilation books or selling a set of Photofact Folders as a lot (with one such listing being listed for $800 for a set of 50 complete Photofact folders that were in no particular order) with only 2 listings that were selling individual folders out of a lot of 50 or 100 Sam's Folders, that I'm assuming came from an old repair shop or an old Library collection.
The one listing that was selling individual folders out of a full lot of Sam's folders had Folder 1045 but it was already sold, and the second listing had 2 Sam's 1045 folders and one had already sold and I had just bought the last one out of that lot.
So it seems that these Sam's folders are getting harder to come by unfortunately.
dieseljeep 07-22-2023, 08:28 AM Greetings everyone, I will be picking up tomorrow locally a mid to late 1960s Sylvania Color TV that appears to be from what I can see of the pictures an all tube Color TV or perhaps a hybrid (I'm not sure becuse the pictures I saw of the inside of the unit were kind of limited to a small area of the main chassis where I saw at least two or three tubes in the picture and the convergence board and the picture tube besides a front view and a back view of the unit with the cover on the back.
The person who listed it on facebook marketplace said her husband picked it up at a garage sale several years back with the intention to fix it up but he lost interest in it, she said that when he powered it up it produced sound but no picture which I'm wondering if either the HV Rectifier is dead or maybe they were too impatient to wait for it to produce a picture, especially if it didn't come equipped with the "instant on" feature. One thing I did notice about the TV from the pictures of the inside of the set that I could see, is that it looks to be a low hours set because it has very little dust built up on the picture tube and on the chassis, and the TV appears to have the original Sylvania picture tube in it yet and the cabinet looks darn near mint.
what do you guys think, will this be a good TV when fixed up and what kinds of things should I look out for when trying to restore this set?
Thanks for your help.
See pictures below.
How did the Masonite back get all broken up.
It must be a curbside pickup, that someone tried to get to the yoke! :sigh:
vortalexfan 07-23-2023, 08:11 PM How did the Masonite back get all broken up.
It must be a curbside pickup, that someone tried to get to the yoke! :sigh:
I don't know how the back cover got broken, I just know that the person I got it from on facebook market place said that her husband picked it up from a garage sale 10+ years ago and intended to fix it up but had some health problems that got in the way of that endevor.
vortalexfan 07-23-2023, 08:20 PM Do you happen to remember the + source those two resistors are fed from? Seems like it as a lot higher than 24V, but I could be wrong. Also I could be wrong on the 27K value, but that's the figure that sticks in mind. A schematic would sure be handy.
According to the circuit Board the + Voltage feeding those resistors is +340 volts.
According to the resistor color coding on the 2 2W carbon comp resistors you're referring to are supposed to be 68k Ohm resistors and then there are 3 green wirewound resistors on the same board that are 27k Ohm 3W power resistors which all measure within spec yet, but the 2 2W Carbon Comp Resistors which are supposed to be 68k Ohms are measuring only 16k Ohms or so, so it sounds like those carbon comp resistors need to go bye-bye, because they are WAAAAAYYYY out of tolerance. :thumbsdn: :sigh:
Probably what I'll do to replace those 2W 68k Ohm resistors is cut them off on either side of the resistor element casing and then solder a new one onto what's left of the wire connectors above the board so that way I don't have to worry about risking damaging the circuit traces underneath the board, since they left about a 1/4" of wire lead above the board surface. :thmbsp: :yes:
old_coot88 07-23-2023, 10:03 PM IMHO you'd be better off waitin for a Sams to double-verify those resistors' value. Code stripes can change color from excessive heat over long duration. Gotta wonder if the two transistors might still be good though.
vortalexfan 07-24-2023, 12:02 AM IMHO you'd be better off waitin for a Sams to double-verify those resistors' value. Code stripes can change color from excessive heat over long duration. Gotta wonder if the two transistors might still be good though.
I have a Sam's on order from feebay, that is an original full 1045 Folder that I got for $13, it supposed to be here sometime this week.
When I get that folder I'll take a look at the manual for the TV and double check the resistor values.
vortalexfan 07-26-2023, 07:08 PM I got the manual for my TV in the mail today and I just confirmed that the 2 2W Carbon Comp resistors in the TV were indeed 68k Ohm 2 watt resistors and what I was measuring on them using my VTVM was about 16k Ohms which is indeed way low.
And I believe that VTVMs can be used to measure resistors in circuit regardless of there being a parallel load on them or not because the VTVM applies a voltage to the resistor when measuring it that makes it read like the resistor is out of circuit, at least that's my understanding of how VTVMs work, compared to DMMs.
old_tv_nut 07-27-2023, 12:19 AM ....And I believe that VTVMs can be used to measure resistors in circuit regardless of there being a parallel load on them or not because the VTVM applies a voltage to the resistor when measuring it that makes it read like the resistor is out of circuit, at least that's my understanding of how VTVMs work, compared to DMMs.
That is not correct for an type of resistance meter. When a resistor is still in the circuit, other conducting paths will be measured in parallel with the resistor, which will make it read low. How much lower depends on what is in parallel in the circuit. This is a property of the circuit, not the meter.
vortalexfan 07-27-2023, 09:59 AM That is not correct for an type of resistance meter. When a resistor is still in the circuit, other conducting paths will be measured in parallel with the resistor, which will make it read low. How much lower depends on what is in parallel in the circuit. This is a property of the circuit, not the meter.
OK, well I guess I won't trust what my VTVM's manual says, because the manual for my VTVM said that it was supposed to be able to read resistors in circuit without the need to clip them out, unless I misunderstood what it was saying?
Anyways regardless the resistors should be easy to clip out of circuit because they do stick up above the board about a 1/4" so which means that if those resistors are actually fine then I can just solder the resistors back onto the leads that were clipped.
Electronic M 07-27-2023, 10:37 AM OK, well I guess I won't trust what my VTVM's manual says, because the manual for my VTVM said that it was supposed to be able to read resistors in circuit without the need to clip them out, unless I misunderstood what it was saying?
Anyways regardless the resistors should be easy to clip out of circuit because they do stick up above the board about a 1/4" so which means that if those resistors are actually fine then I can just solder the resistors back onto the leads that were clipped.
Two things:
One while you can measure resistors in circuit with any resistance meter the reading in circuit is never guaranteed to be the actual resistance of the resistor due to parallel paths. No meter can eliminate parallel paths...If it claims to, it's lying. When measuring resistor in circuit if the value is exactly as rated or higher it's probably accurate, if it's lower you have to unhook one lead.
Two it's really better to pull the chassis and solder on the board than clip and tack it back together, both from a neatness standpoint and from a on thicker leads to get a good joint you can end up melting the old board joint causing the lead to fall through the board or a cold solder joint on the board to develop standpoint.
vortalexfan 07-27-2023, 11:55 AM Two things:
One while you can measure resistors in circuit with any resistance meter the reading in circuit is never guaranteed to be the actual resistance of the resistor due to parallel paths. No meter can eliminate parallel paths...If it claims to, it's lying. When measuring resistor in circuit if the value is exactly as rated or higher it's probably accurate, if it's lower you have to unhook one lead.
Two it's really better to pull the chassis and solder on the board than clip and tack it back together, both from a neatness standpoint and from a on thicker leads to get a good joint you can end up melting the old board joint causing the lead to fall through the board or a cold solder joint on the board to develop standpoint.
OK, well anyways with one of the legs of the resistors removed from the circuit, my VTVM (which for some reason that's all I could find, because I somehow misplaced my DMM) the resistors read 75K Ohm which is higher than the rated 68K Ohms, and those resistors are 10% tolerance so I don't know if they are measuring within tolerance or not but it still sounds like they may need to go either way.
I was reading/following another member's thread where he was repairing a Color TV of a similar vintage to mine (the one where he was working on a late 1960s Motorola Color TV that had issues with the color not wanting to lock in correctly) and there were some suggestions about using some 2%-5% tolerance resistors in the IF and Chroma sections of the TV to get it to work better.
I wonder if in my TVs case that might be something worth looking into to get the TV functionality more stable, because my TV is essentially exibiting those same issues as that Motorola TV in the aforementioned thread, where the picture and color are not stable. :scratch2:
vortalexfan 07-27-2023, 02:22 PM UPDATE: I was able to locate my DMM and I was able to confirm tha those resistors were indeed around 75K ohms so like I said I'm guessing that is way above the 10% tolerance the resistors are rated for so I'll need to replace those for sure.
So according to my calculations the resistors are just barely outside of the 10% tolerance range, 74,800 Ohms and under is within the 10% tolerance range of the 68K Ohm resistors and the resistors were measuring 75,300 Ohms... :sigh:
Which is probably the reason why those resistors haven't cooked themselves yet and also probably the reason why the transistors may not of fried yet, but are still affecting the picture quality, but also I haven't ran the TV for more than a few minutes at a time to do some troubleshooting and shutting it off in between.
vortalexfan 07-27-2023, 03:22 PM One thing I'm curious about, how do you get the chassis out of the cabinet on this TV?
I know with my past experience with working with color TVs (small portable color sets from the 1980s) is that you can't tip color picture tubes face forward because you can ruin the picture tube, and the way the chassis is fastened to the cabinet in this TV it seems like the only way to get to the screws is by tipping it on end but with this being a rather heavy solid wood (pecan wood?) cabinet its going to be kind of tricky to get the cabinet tilted on its side without damaging anything.
Any advice on how to do this safely without risk of hurting myself or the picture tube or the cabinet?
Thanks for your assistance.
old_tv_nut 07-27-2023, 05:33 PM I haven't heard of problems caused by tipping a picture tube forward. Camera tubes, yes, but not picture tubes.
vortalexfan 07-27-2023, 06:21 PM I haven't heard of problems caused by tipping a picture tube forward. Camera tubes, yes, but not picture tubes.
That's interesting because I've worked on several old portable color TVs from the 1980s and and even a few non-portable units from the 1980s that when I tipped the TV forward (or maybe it was on its side) the picture tube would get messed up by looking like someone ran a powerful magnet across the screen and that would be the end of the TV.
Any ideas as to what I was experiencing and what would be the best way to avoid that?
dieseljeep 07-27-2023, 06:26 PM That's interesting because I've worked on several old portable color TVs from the 1980s and and even a few non-portable units from the 1980s that when I tipped the TV forward (or maybe it was on its side) the picture tube would get messed up by looking like someone ran a powerful magnet across the screen and that would be the end of the TV.
Any ideas as to what I was experiencing and what would be the best way to avoid that?
You have to use a degaussing coil. I also used a tape demagnetizer.
Several ways to handle chassis
GOOD
Remove legs if it has them. they either unscrew or twist off. Put the
set on its side & remove all but one rear chassis bolt. The chassis will swing out to work on.
BETTER
Same idea. Put TV on bench upright with a few feet behind it. Find a box
about the same HGT, pull chassis & flip out onto box.
BEST
A test jig but you dont have one !
BTW the purity will be way off while on its side running. Also just
be sure you dont pull wires too tight. Take it slow.
73 Zeno:smoke:
LFOD !
Electronic M 07-28-2023, 09:00 AM For chassis removal I forget if the D12 was this way(I think so but it's been like 5 years since I had mine apart), but the D16 definitely is....On Sylvania sets of that era the chassis slides into 2 side rails and locks to those rails with 2 rear facing screws. Remove the screws and unplug all wires and the chassis just slides out the back.
I've never worked on 80s inline sets or seen what you describe. Delta gun sets like this Sylvania don't care about orientation* and replacements were shipped face down.
*In service they would sometimes need purity adjustment and or degauss when moved from facing north-south to east-west but no permanent issues otherwise.
vortalexfan 07-28-2023, 10:17 AM For chassis removal I forget if the D12 was this way(I think so but it's been like 5 years since I had mine apart), but the D16 definitely is....On Sylvania sets of that era the chassis slides into 2 side rails and locks to those rails with 2 rear facing screws. Remove the screws and unplug all wires and the chassis just slides out the back.
I've never worked on 80s inline sets or seen what you describe. Delta gun sets like this Sylvania don't care about orientation* and replacements were shipped face down.
*In service they would sometimes need purity adjustment and or degauss when moved from facing north-south to east-west but no permanent issues otherwise.
OK so it sounds like it what I experienced with the 1980s Color TVs was something unique to the inline gun style picture tubes which were more common then, whereas the Delta Gun style picture tubes from the 1960s and 1970s didn't suffer from the issue I described. :scratch2:
vortalexfan 07-28-2023, 10:20 AM And thanks for the advice for how to go about removing the chassis from the cabinet, this TV I'm working on does have legs but I'm not sure if I want to fiddle with trying to remove them and trying to move this TV to my work bench in the basement, as it is kind of heavy. so I think I'll try Electronic M's Advice and see if I can just slide the chassis out of the cabinet.
old_tv_nut 07-28-2023, 03:29 PM That's interesting because I've worked on several old portable color TVs from the 1980s and and even a few non-portable units from the 1980s that when I tipped the TV forward (or maybe it was on its side) the picture tube would get messed up by looking like someone ran a powerful magnet across the screen and that would be the end of the TV.
Any ideas as to what I was experiencing and what would be the best way to avoid that?
This sounds like the shadow mask was previously broken loose and got permanently dislodged when you tilted it.
vortalexfan 07-29-2023, 12:00 AM This sounds like the shadow mask was previously broken loose and got permanently dislodged when you tilted it.
OK thanks for letting me know.
vortalexfan 08-03-2023, 08:44 AM UPDATE: I finally got around to removing the chassis from the cabinet and I tested the electrolytic caps and they all tested good yet according to my ESR Meter, and that would make sense seeing as the TV still had full screen deflection.
I also poked around and tested a few of the resistors on the various boards in the TV and the resistors for the most part tested within specs yet, those two 68k Ohm 2W resistors were the only resistors that measured out of tolerance and so I put in an order for some over at Digikey (because Mouser didn't have any 68k Ohm 2W Resistors in stock unfortunately) also the two 68k Ohm 2W resistors were the main resistors you guys said would give me the most trouble.
I also was able to clean the pots and the switches better with the chassis out of the cabinet.
vortalexfan 08-09-2023, 04:33 PM UPDATE: I finally got those two 68K Ohm 2W Resistors replaced.
But I have a question about a couple of capacitors I saw in the chassis that look like they might be paper caps but I'm not sure because there were film caps that looked like these types of caps as well, and plus it seems a little odd that they would of been using paper caps in the late 1960s when Mylar/Film caps were the predominate type of capacitor in use by that period in time.
See pictures below.
vortalexfan 08-10-2023, 12:57 AM OK, so I've pretty much replaced every single tube in the TV except the Vertical Output/Vertical Oscillator Tube which is a 6LU8 tube which I unfortunately do not have in my stash, and the Color Output Tube which is a 6MD8 tube, both of which are compactron tubes and both of which I do not have access to in my tube stash; this is odd because all of the other tubes in this TV I had at least one or more of in my tube stash, and most of them were Sylvania branded tubes ironically enough.
Unfortunately all I'm able to get the TV to do right now is to do a barber pole effect when I have the color turned on, and the vertical isn't locking in at the right frequency, its running at half frequency right now (where the picture is showing a bar in the middle and the top half of the screen shows up at the bottom and the bottom half shows up at the top half of the screen.)
I've tried adjusting the height and linearity controls on the back and it doesn't seem to help much (which is why I'm thinking the Vertical output and oscillator tube is either weak or bad.)
I'm guessing that the barber pole effect (the color not locking in) is either due to a bad color output tube, a bad 3.58 MHz Crystal, or the color demod transistors are bad.
old_tv_nut 08-10-2023, 10:48 AM Barber pole effect is a color oscillator/AFC adjustment issue. The oscillator is running, so the crystal is likely OK. Color demod and/or color outputs cannot cause this.
Lack of oscillator lock could also be caused by burst gate/burst amplifier problem.
Electronic M 08-10-2023, 10:52 AM In the vertical circuit I would look at out of tolerance resistors and maybe leaky capacitors.
Having owned 3 different color Sylvanias I've found that when the vertical is off frequency subbing the vertical tubes usually doesn't help.
vortalexfan 08-10-2023, 12:07 PM OK, thanks.
I'll look into the vertical deflection board and see if there are any bad resistors in there or capacitors.
Although I would be kind of surprised that with this thing using mylar caps in most of the circuits that there would be any leaky capacitors causing any issues, but then again anything can happen in a 50+ year old TV... :scratch2:
vortalexfan 08-16-2023, 02:13 PM OK so I had ordered a couple of new Vertical Output/Oscillator Tubes for the TV because I wanted to see if that would make a difference in the operation of the vertical operation, and I installed a new 6LU8 tube into the TV and the TV did something it never did before which was that some of the components on the sweep section board started arcing against each other and then the Horizontal Output Tube was arcing between the grid cap and the High Voltage Cage.
The TV does have a fair amount of dirt and grime built up on the circuit boards themselves but the inside of the HV cage and the Picture tube itself are spotless which is why I said I thought it might of been a low hours set but the dirt and grime buildup on the boards was just from the fact that the TV was stored in the previous owner's garage for many years.
Would the dirt and grime buildup on the circuit board be the possible cause for some of the arcing I'm seeing inside the TV?
vortalexfan 08-16-2023, 05:24 PM Here's a photo of what the TV is doing right now.
Pardon the glare on the screen, the room I'm working on the TV in has two south facing windows which were creating some glare on the screen, and the color setting on the front of the screen was turned all the way down which is why there's no color right now (I want to try and get the vertical deflection and AGC issues straightened out before I concern myself with the color issues.)
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