View Full Version : 1968 Zenith Color Set 20Y1C50 Chassis


pendulum
08-27-2015, 06:22 PM
Bought this set today at an estate sale for $40. Set is in decent condition. Here is a photo of the set after I got it home. I have the knobs but I removed them for transit. The brown gunk came off with cleaning.

http://i290.photobucket.com/albums/ll246/eviljoebob/IMG_2340.jpg (http://s290.photobucket.com/user/eviljoebob/media/IMG_2340.jpg.html)

Unfortunately when I took the back off it was obvious some animal activity had been going on. I don't know how they got in with the back on, but whatever. Despite how it looks the seeds and cloth were near the front of the chassis and the animals didn't get under the chassis, so overall the chassis is ok.

http://i290.photobucket.com/albums/ll246/eviljoebob/IMG_2341.jpg (http://s290.photobucket.com/user/eviljoebob/media/IMG_2341.jpg.html)

Here is the chassis. Looks bad but most of the rust looking spots must be urine and fur/cloth and they wiped off fine with water.

http://i290.photobucket.com/albums/ll246/eviljoebob/IMG_2346.jpg (http://s290.photobucket.com/user/eviljoebob/media/IMG_2346.jpg.html)

Most of the tubes have been replaced. Tubes are a random mix of sylvania, dumont, ge, zenith, and a brand I have never heard of, realistic lifetime

http://i290.photobucket.com/albums/ll246/eviljoebob/IMG_2347.jpg (http://s290.photobucket.com/user/eviljoebob/media/IMG_2347.jpg.html)

The only problem with the chassis is there are a few wires that have been chewed, two of these jumper style wires, which I can easily change, and the cap cable for the horizontal output tube. That wire I may try just covering with silicone, because changing that wire would be a bit difficult and I have seen others do this before and having it work.

http://i290.photobucket.com/albums/ll246/eviljoebob/IMG_2350.jpg (http://s290.photobucket.com/user/eviljoebob/media/IMG_2350.jpg.html)

The underside of the chassis doesn't look like it has ever been touched. I did see that the thermistor was falling off and when I touched it the think fell and broke apart, so I will have to change that.

http://i290.photobucket.com/albums/ll246/eviljoebob/IMG_2349.jpg (http://s290.photobucket.com/user/eviljoebob/media/IMG_2349.jpg.html)

The next thing I looked at was the crt. The key fell off when I unplugged the socket, maybe the set took a hit at one point. The crt had vacuum though, but the crt is just about done. All three guns tested well into the bad. Life test wasn't terrible, but at this point that is not going to make a difference. Luckily these crts (25gp22) are much more common that round color tubes and I have wanted to get a brand new crt for a while now.

http://i290.photobucket.com/albums/ll246/eviljoebob/IMG_2351.jpg (http://s290.photobucket.com/user/eviljoebob/media/IMG_2351.jpg.html)

One thing I am looking for though is the plastic piece that holds these centering magnets as mine is falling apart.

http://i290.photobucket.com/albums/ll246/eviljoebob/IMG_2348.jpg (http://s290.photobucket.com/user/eviljoebob/media/IMG_2348.jpg.html)

Also, the uhf knob had broken in half. I was able to glue the two parts together, but if anyone has a replacement one I would like one that looks better.

http://i290.photobucket.com/albums/ll246/eviljoebob/IMG_2352.jpg (http://s290.photobucket.com/user/eviljoebob/media/IMG_2352.jpg.html)

I won't be able to work on this set soon since I am going to school, but I will work on it over the winter. I like the set, it would be neat if it was a remote set but overall I think it is quite neat.

Electronic M
08-27-2015, 07:14 PM
That brown stuff is glue that was supposed to hold on a piece of metal with control labels on it....Which I assume you don't have.

Realistic was the house brand of Radio Shack if that tube is bad you might be able to get a free warranty replacement from them.

Classic mouse intrusion...If they can find a hole big enough to get their head through they can get in.

Do you know what handle that knob had? I may have a spare for it.

pendulum
08-27-2015, 08:41 PM
Here is a photo of what the knobs look like for this set. Hope this helps.

http://i290.photobucket.com/albums/ll246/eviljoebob/IMG_2354.jpg (http://s290.photobucket.com/user/eviljoebob/media/IMG_2354.jpg.html)

rca2000
08-27-2015, 09:09 PM
Your CRT MAY just be asleep. We have seen this MANY times. A CRT will show very low emission...at FIRST_-when it is first checked after sitting for MANY years. I recently saw this on a 22 inch late 70's BW tube. it showed VERY low--at first. So...I 'gassed it a bit"--by turning the filament to about 7.5 volts....and it did NOT take long...before the meter on my CR-70 (which has a MUCH bagger "bad' range than yours does), was reading into the "good" range. After a few miutes of this...I was then able to reduce the filament to 6.3 volts and the tube STILL showed int the good range. before too long..it would show good at FIVE volts on the filament !! And life test holds WELL...moving just a BIT--and NOT into the red--after 20 seconds.

So..DO THIS...with yoiur tube. Crank the filament to about 7-8 volts...and let it sit tihs way--for at least five minutes. If you STILL get no better results...go to 8.5 volts for 10 minutes. If after THAT...the meter STILL does not go up apprecibly..the tube may indeed be gone. but I WOULD try to save it first--CRT's Are NOT that easy to come by anymore !!

andy
08-28-2015, 01:34 AM
...

zeno
08-28-2015, 06:41 AM
The plate cap is easy to change. The metal cover under
the HV rectifire door comes off with three 1/4" bolts.
The FBT board is there & the focus components.
Most purity rings come with the blue lateral also. You
can take one off almost any delta tube. Newer Zeniths
use a very nice one. IF you change the jug see if you can
find a newer chroma color. It will look much better.

Livestock in TV's were a big problem. Once I opened a set
& a roach as big as a Buick came walking out. Two of
us unloaded on it with freeze mist. Damn thing pulled a
Walt Disney a half hour later, flipped over & started walking again !
A hammer finnished the job.

73 Zeno:smoke:

pendulum
08-28-2015, 07:18 AM
I retested the crt today. I think the socket may not have been fully on yesterday because today the crt does test good. The life test is still not great though, so I think I still will look into getting a new crt, because I have always wanted to put a nos crt in a set. I will keep the old tube though in case it is ever needed.

Marco-nix
08-28-2015, 07:59 AM
You got a nice set but finally you paid too much ..my opinion .

Findm-Keepm
08-28-2015, 08:24 AM
Nice find, I too would have popped for the full $40. Tube sets around here are increasingly hard to find - the last one I saw available was a 21" black and white on CL, and had a broken CRT.

I think it's a geography thing - we here on the East coast have no basements to store stuff in, and the 35% turnover in population here every three years (we're a Navy town) means we don't see a lot of older items available.

Lemme know if you still need the Blue lateral/Centering Rings - I have one I can send you, for postage.

Cheers,