1964 Zenith 5111 comes to life!

[DaveWM]

I would look in the color burst amp tubes. What ever you do, dont be tempted to started adjusting any coils. It was working fine so the coils did not suddenly jump out of tune.

[miniman82]

Some old sets need a tweak or they're never gonna work right, IMO. Both my CTC-7 and CTC-4 needed chroma alignments done (and done and done) till they worked correctly- remember that when you're replaceing parts like caps, the circuits they are in might need alignment after the recapping is done. That's because the caps you put in will invariably have a different value than the ones you took out, so it makes sense to have to make at least a few tweaks here or there. The CTC-4 in particular refused to receive a color program till I messed with the local oscilator, I guess it wasn't even running till I gave a certain coil a touch, and then it was off to the races.

[DaveWM]

Perhaps a tweeking of coils can help a set thats not perfect, but to go from working fine to zero color ,with nothing done in between, does not sound like spontanious slug movement.

I would stick with the basics until better knowledge has been aquired on what do to.

Start by wiggling tubes, then move on B+ checks, then plate and screen checks of the burst and chroma amp tubes.

My guess is a loose tube/bad tube/open power resistor (perhap taken out by a shorted tube).

[ctc17]

Let the set run for a few hours, does the color pop in? Try running the fine tuning up to the edge and see if you get the barber polling rainbow or if the color pops it.

One of the common things I run into is the color crystal will take a dump a few days after returning to service. Usually they lock in as they heat up.

Defiantly dont turn any cores. I have aligned several color sets and its not something you want to mess with unless you have the equipment and practice.

If you try the things Dave mentioned and you dont get anywhere I wouldnt hesitate to change the crystal. Just based on what I have seen with the 50 tube color sets I have.

One other thing to try.
let the set warm up good, make sure the color level is up, run the fine tuning up, now tweak the horizontal hold from one side to the other. till it looses lock on both sides. If color pops in or you get the floating rainbows while moving the horizontal hold its a fairly good indication the crystal has drifted.

Does the fine tuning even work? These are well noted for the fine tuning plastic gear cracking and not turning.

[Phil Nelson]

Originally Posted by Tubejunke

Well folks, I guess the nearly inevitable had to happen sometime.

Not to be a spoilsport, but if you are still running it with 100% original capacitors, that is really tempting fate. That has the potential to be a beautiful performer, but if you burn up the flyback or power transformer, you will kick yourself. I would pull out the power plug until you save up enough to replace the electrolytic capacitors.

Just my $0.02.

Phil Nelson

[ctc17]

Not to start a war here.....the mid 60s tvs on are not like the old bw stuff. The electrolytics rarely go bad. Zenith used some superior quality parts.
You can actually diagnose these to a specific failed part rather that shotgun replace a group of parts.

[Tubejunke]

Originally Posted by ctc17

One other thing to try.
let the set warm up good, make sure the color level is up, run the fine tuning up, now tweak the horizontal hold from one side to the other. till it looses lock on both sides. If color pops in or you get the floating rainbows while moving the horizontal hold its a fairly good indication the crystal has drifted.

Does the fine tuning even work? These are well noted for the fine tuning plastic gear cracking and not turning.

WOW! I have never gotten this much attention and advice about any set, but thanks to everyone just the same. This post will touch base on various comments and ideas given in the last few posts by different members. First, the fine tuner works just fine. Next, I checked all color related tubes and all three video stages. One of the first rules of troubleshooting is a good use of the senses and looking and sometimes moving things around a bit like tubes, wire connectors, and potentiometers, so I have pretty much covered the easiest but often overlooked possibilities. The visual inspection is why I mentioned the seemingly cracked spool of the horizontal efficiency (linearity?) coil, but I was not indicating that I would never start turning coil adjustments knowing that the set was working almost perfectly up to a point. I will say that I can't make the horizontal hold lose lock in both directions; only around 3/4 clockwise, but it locks steady. I don't want to elaborate too much on the fact that some small issues may lie in sections other than color producing sections so the focus for now remains getting color back.

I am thinking about this crystal that CTC-17 mentioned because from the get go the color took a few minutes of warm up time to come in, then it seemed stable. The last time it produced a color picture, nearly a half hour had passed and I was ready to give up for the evening when the nice color suddenly popped in. Last night I could not achieve any color other than some strange effects when I tweaked the color killer a bit. I just set it back where it was because again, adjusting a bunch of things that don't need adjusting would be ridiculous, but I am sure that a lot of people make that mistake.

I know that capacitors can be unpredictable in old sets, but frankly I have found more old paper foil capacitors to be problematic than electrolytics in my adventures with old 40s-50s black and white sets. So far all of the cans run nice and cool as does the power transformer, so for the moment I feel OK about the electrolytics, but I have not checked any of them. I only have a good Simpson analog meter for that which I know is not a "for sure" insurance that a capacitor is good or bad. Believe it or not, the main electronics supply house in this area has capacitors that are NOS and are probably nearly as old as the ones in this set. I don't see any paper caps underneath; only black or brownish non polarized "orange drop" types. I don't know how prone to failure those are. I know that this subject is always sort of up in the air; again I am trying to stay focused on color for now.

I have mentioned before in other posts that I owned a few color "roundies" as a kid for daily use just because I liked the way they looked and generally thought that the picture was better. Back then I did little or no repair on the color sets; my interests then and for years to come was primarily old black and white sets. So, I am more new to the vintage color TV operation and repair than to repair in general. I have been messing around with tube type radios and TVs for nearly 30 years. Admittedly, no formal training was involved other than one year of HS electronics until I was lucky enough to enter the electronics degree program at the local community college where I am to graduate in May. One of the things that I love about electronics is that you never stop learning! If you do, then pick up a Boolean Algebra book and start racking your brain with digital logic! Thanks to everyone for pitching in some opinions and ideas. It is great that there are sites like this where knowledge can be passed along that is not taught in any school!

[Phil Nelson]

Originally Posted by ctc17

Not to start a war here.....the mid 60s tvs on are not like the old bw stuff. The electrolytics rarely go bad. Zenith used some superior quality parts.

I've found bad electrolytics in newer gear than that, but haven't worked on any 1960s Zenith sets, so I'll take your word that their parts are that good. Maybe I need to switch brands

I used to think that the brown/maroon "orange drop" types were pretty good, but not so much any more. This week I went back through an RCA CTC-11 that I restored a couple of years ago and replaced about ten of them. They had seemed fine at the time, but didn't hold up -- creating problems with vertical linearity and horizontal stability. Nothing is forever, I suppose.

Phil Nelson

[DaveWM]

Same here on zenith filter caps, more likely than not they are fine. I have worked on several zeniths from the early to late 1960's so far only one was a problem and it was open (the pincushion correction on a 23x). Not only have the cans been ok, but to my surprize even the singles have tested well. I use my cap tester on them to test at rated voltage for open and leakage, so far they test every bit as well as new caps! So I have revised my thinking these days to check them, if they test like new I leave them be. I do like to add fuses to the B+ and HOT, the B+ fuse will cover the PT and the HOT will cover the fly if the horz osc decides to stop. The HOT fuse is a little tricky, CTC-17 has done some testing and a reg fuse does not seem to work properlyt here, a chem fuse would be the way to go.

Prob the best advise would be to check the HOT current and work on it if too high. Also you can prolong the sets life by reducing the line voltage, this will take a large load off. the set should work fine at 110vac, around here its often at 125vac. I have not done it yet but a adj to the HOT screen value would prob be the best way to address the higher line voltage put out today


I would recommend ALWAYs changing the coupling cap to the HOT, esp if its a brown/maroon drop. Also the 1kv hard covered (white tube) foil caps that are generally found in the vertitcal circuit. Those seem to be bad about 50% ot the time (leaky) you will know if the picture seems to be jumpy vertically.

[ctc17]

Originally Posted by Tubejunke

WOW! :

I am thinking about this crystal that CTC-17 mentioned because from the get go the color took a few minutes of warm up time to come in, then it seemed stable. The last time it produced a color picture, nearly a half hour had passed and I was ready to give up for the evening when the nice color suddenly popped in. Last night I could not achieve any color other than some strange effects when I tweaked the color killer a bit. I just set it back where it was because again, adjusting a bunch of things that don't need adjusting would be ridiculous, but I am sure that a lot of people make that mistake.

Yep, change the 3.58 crystal, its ok to use the small form factor one they sell in the blister pack at the local electronics store. Its a $2 part max. If you dont have such a thing locally I can send you one.

[ctc17]

Originally Posted by Phil Nelson

I've found bad electrolytics in newer gear than that, but haven't worked on any 1960s Zenith sets, so I'll take your word that their parts are that good. Maybe I need to switch brands

I used to think that the brown/maroon "orange drop" types were pretty good, but not so much any more. This week I went back through an RCA CTC-11 that I restored a couple of years ago and replaced about ten of them. They had seemed fine at the time, but didn't hold up -- creating problems with vertical linearity and horizontal stability. Nothing is forever, I suppose.

Phil Nelson

Tell me about these.....I had a ctc35 I fought with for weeks on a vertical problem and it turned out to be one of these. They get lossy, change value when dc voltage is applied and drastically change value with temperature. I have had to replace more orange drops than electrolytics in 60s stuff.

Even though I hate to do it and admit it, the time is here when all the orange drop style need to be changed.

[DaveWM]

a old school cap tester is a good piece of gear to have, both for checking eletros and lossy film types. The dipped types (brown orange maroon) often test fine for leakage, but not so for values. They show up on the tester as a eye that does not fully open or has fuzzy edges. Heat seems to have big effect as well when they are bad.

I also check anything going in as a replacement. I have caught at least once my self installing the wrong value. Goes like this, I lift a leg test it, dial in the correct value, eye does not open up as it should. Remove the old part, get ready to install the new one, but put on the tester, hmmm thats odd its not opening at all. Ah Ha, I have a .01 not a .001, by leaving the tester dial in the orig position used to test the old cap it caught me try to replace it with a cap off by a factor of 10.

other cap tester oddness, disconnect any RF leads, I had a DVD player hooked up to a set, and turned on. Set is off and unpluged, lift one leg to test test bad (fuzzy eye on value test) take out of circuit test again, test fine. hmmm put back in, fuzzy eye, disconnect the DVD, and all is well.

make sure cap tester case is isolated from the metal chassis of the set, did not do that once and a cap kept testing as leaky. Not sure why but the cap tester was in contact with the TV chassis. moved it and everything tested normal.



stuff happens....

[old_coot88]

Originally Posted by Tubejunke

...Last night I did try adjusting the color killer pot and could easily see that it definitely needs cleaning by its somewhat erratic reaction. However, no matter what adjustment I made I never saw an actual color picture. When I turned it up (or clockwise) I would get what I would call color bleeding into the black and white raster, so I turned it back down.

Try this - turn the color killer back to where you get that "color bleeding" and leave it there. Keep the front panel Color control to maximum. Adjust the fine tuning to the point where the color "should be". The 'bleeding' that you see indicates the chroma signal is getting through to the demodulators, minus the 3.58 referance signal from the oscillator. I.e., the oscillator is not running.

The following applies more to RCA and RCA clone sets, so I'm shooting from the hip with an "educated guess" that it is applicable to Zeniths also.
Before messing with the crystal, find the "reactance" coil and check it for continuity. It is a slug-tuned coil with a single winding (no secondary). It's the 'color sync' adjustment used for locking the 3.58 oscillator. This coil was prone to going open intermittently from thermal expansion, or staying open, causing the osc. to not run.

If you had good color and it was strongly in sync (no barberpoling), I would be less prone to suspect the crystal.
Bill(oc)

[miniman82]

Originally Posted by ctc17

Not to start a war here.....the mid 60s tvs on are not like the old bw stuff. The electrolytics rarely go bad. Zenith used some superior quality parts. You can actually diagnose these to a specific failed part rather that shotgun replace a group of parts.

Ditto, that Philco roundie I just got has all original parts in it and it runs cool as a cucumber. Plus since it's an ugly mid 60's set, I could care less if it burns up.

[Tubejunke]

Originally Posted by old_coot88

Try this - turn the color killer back to where you get that "color bleeding" and leave it there. Keep the front panel Color control to maximum. Adjust the fine tuning to the point where the color "should be". The 'bleeding' that you see indicates the chroma signal is getting through to the demodulators, minus the 3.58 referance signal from the oscillator. I.e., the oscillator is not running.

If you had good color and it was strongly in sync (no barberpoling), I would be less prone to suspect the crystal.
Bill(oc)

Hi Bill, thanks for another idea to look into. I will do some more experimenting with the set this weekend and log a specific list of what is displayed on the screen. My mention of "bleeding" may not be a very descriptive term. Basically, when I turned the color killer clockwise, I saw hints of color in odd places like the lights on top of a cop car, but black and white in most other portions of the raster. These places were the wrong color with too much amplitude. Yes, the picture was strongly locked before as seen in the pictures.