1975 Zenith Solid State console no color demod

[Mangie]

Well, to my surprise its working now. Not sure what it was that caused the problem. But I pulled several cap's off the horizontal board, all tested good. went ahead and tested the transistors and they were ok too. Pulled a few molded plastic caps for the heck of it and they all were good. Just for some fun I replaced them with orange drops. reflowed the whole board. Pulled the big horizontal transistor out, it also tested good. the leads were crusty though. I cleaned them up with a razor and crimped down the pins and reseated it. so I suppose of them things.

Still no color though, so ill start poking at that next.

https://photos.app.goo.gl/hXyRrqWcwD9B8q3f7

[zeno]

Originally Posted by Mangie

You recon that orange safety cap needs replaced? I just so happen to have the exact same one on hand new in the package that was part of a tube sale not long ago

If it was an earlier chassis with a white one I would change it BEFORE doing
anything else. But yours is OK. This is the process with the white one:
Cap opens but does NOT disable the HV. ( was designed to ).
HV goes up to abt 40 KV & set starts arcing.
Arcing blows vert module & DC gets on the vert yoke winding.
Winding heats up & cuts the neck off the CRT
Same thing happend to some Magnavox sets too.

Set looks very strong so should run near new when done.

[dieseljeep]

Originally Posted by zeno

If it was an earlier chassis with a white one I would change it BEFORE doing
anything else. But yours is OK. This is the process with the white one:
Cap opens but does NOT disable the HV. ( was designed to ).
HV goes up to abt 40 KV & set starts arcing.
Arcing blows vert module & DC gets on the vert yoke winding.
Winding heats up & cuts the neck off the CRT
Same thing happend to some Magnavox sets too.

Set looks very strong so should run near new when done.

I don't think the "G" line used the white cap! Some "E's" did!
Going OOT, I ran into a Magnavox that had that capacitor and the replacement was made by the same company, but looked different! American Radionic finally got it right.

[Mangie]

Originally Posted by zeno

If it was an earlier chassis with a white one I would change it BEFORE doing
anything else. But yours is OK. This is the process with the white one:
Cap opens but does NOT disable the HV. ( was designed to ).
HV goes up to abt 40 KV & set starts arcing.
Arcing blows vert module & DC gets on the vert yoke winding.
Winding heats up & cuts the neck off the CRT
Same thing happend to some Magnavox sets too.

Set looks very strong so should run near new when done.

Last night I was just watching a video on a zenith on Jordan Pier's channel and he was talking about that. Yap, I definitely don't want that happening.

CRT tester showed all guns really strong, however when I first turn it on, she has a pretty strong blue tint. Doesnt take long before it returns to black and white. besides that it seems strong and has waaay plenty bright enough screen. I am really excited when I get this finished and watch the nightly news on it. It's my first Zenith and I think I really really like this set so far. I already want another one lol.

but so far im striking out on the color problem. I cant find any bad parts. only thing that was off was some pins on the IC chip has the correct voltage and a few that are suppose has none. so I replaced the chip, reflowed everything. but no change to the problem. I went ahead and ordered a nos chroma board to see what happens.

[zeno]

Originally Posted by dieseljeep

I don't think the "G" line used the white cap! Some "E's" did!
Going OOT, I ran into a Magnavox that had that capacitor and the replacement was made by the same company, but looked different! American Radionic finally got it right.

The recall was
17EC45 19EC45 23EC45 25EC45 runs # 401 & higher
Before run 401 sets used separate 22-5001 caps, 5 of them IIRC.
They should be changed also.
17FC45 19FC45 23FC45 25FC45 all runs.
From G line up they all used Sprague orange.

Funny story. A Sprague rep lived in town. Zenith was a great customer
to them & they gave him an Avante. Damn cap opened & necked his CRT !
Absolutely true. Dont be vague, ask for Sprague !

Zeno

[Electronic M]

Originally Posted by zeno

The recall was
17EC45 19EC45 23EC45 25EC45 runs # 401 & higher
Before run 401 sets used separate 22-5001 caps, 5 of them IIRC.
They should be changed also.
17FC45 19FC45 23FC45 25FC45 all runs.
From G line up they all used Sprague orange.

Funny story. A Sprague rep lived in town. Zenith was a great customer
to them & they gave him an Avante. Damn cap opened & necked his CRT !
Absolutely true. Dont be vague, ask for Sprague !

Zeno

Was it a Sprague made cap? I'm fairly sure the later orange drop safety caps were Sprague, but I forget who made the lousy white ones.

[init4fun]

Originally Posted by zeno

Dont be vague, ask for Sprague !

Zeno

[zeno]

Originally Posted by Electronic M

Was it a Sprague made cap? I'm fairly sure the later orange drop safety caps were Sprague, but I forget who made the lousy white ones.

The bad ones were American Radionics & white in color. Good ones were Sprague and orange.
The idea was with separate caps ( 22-5001 ) a few could open, symptoms
noticed & repaired. But too many ran their sets & the tripler, divider and CRT
socket would go bad. Typical repair on a flat chassis was above & sometimes
the hoz out.
On 4 lead caps one cap did all. In theory if the cap opened the interlock(s)
opened & HV killed. Problem was the AR caps didnt ! It took a while to
show up. By that time hundreds of thousand sets had a time bomb built in.
Funny thing is I saw sets with the AR caps up til the 90's that never
went bad & Zenith still gave a a free one for every one we brought
back.

enuf fer now
73 Zeno
LFOD !

[damen]

We always changed all those white 4 lead caps, but, I seem to remember our Zenith distributor telling us the white ones with black writing on them were the recalled ones, but the ones with blue writing were okay. Has anyone else ever heard this ?

[Mangie]

Got the new old stock chroma board. Still no color though, not even the barber polling. I haven't yet found what's wrong with it. It does however let me adjust the ACC voltage where the original doesn't.

[Mangie]

Cant believe it but I got it working!
Decided to take a closer look at the original Chroma board as it was sorta working. I dont know how I didnt notice this. But someone had did some modifications to the board, removed a cap and placed it across some resistors and added another resistor in series to another cap. I followed the sams closely and got everything in their proper places. Still didnt work at that point. was kinda at a loss at that point. Then I thought id change that other IC chip for S&G's and to my shock it started working! Man this has been kicking my butt, really didnt think id get it going.

[Jeffhs]

Originally Posted by Mangie

Cant believe it but I got it working!
Decided to take a closer look at the original Chroma board as it was sorta working. I dont know how I didnt notice this. But someone had did some modifications to the board, removed a cap and placed it across some resistors and added another resistor in series to another cap. I followed the sams closely and got everything in their proper places. Still didnt work at that point. was kinda at a loss at that point. Then I thought id change that other IC chip for S&G's and to my shock it started working! Man this has been kicking my butt, really didnt think id get it going.

I am glad you were able to restore your TV, even though it took a lot of work to do it. Those older Zeniths are well worth it, IMHO.

Zenith was an American electronics firm, founded in 1918 which should not, IMO, have left Chicago for Korea after many years and decades of producing quality TVs, stereo systems and televisions. (Zenith's slogan "the quality goes in before the name goes on" fit this company perfectly, IMO.) I had their model IS-4041 four-mode stereo system for 17 years, not to mention two Zenith 13-inch color TVs and a Zenith 19-inch color set; I still have the 19-inch set which still works, although it is presently gathering dust in my bedroom since the DTV changeover in 2008. I will not be using it again, since I would need to rent a cable box from Spectrum, the TV provider here, and I simply do not want to spend any more money for TV for any reason unless I need to replace my present 32-inch Insignia HDTV some day. I have what Spectrum refers to as "streaming" video service, which does not use or require a box; this suits me to a T since I am a senior citizen on a fixed income.

[Mangie]

Originally Posted by Jeffhs

I am glad you were able to restore your TV, even though it took a lot of work to do it. Those older Zeniths are well worth it, IMHO.

Zenith was an American electronics firm, founded in 1918 which should not, IMO, have left Chicago for Korea after many years and decades of producing quality TVs, stereo systems and televisions. (Zenith's slogan "the quality goes in before the name goes on" fit this company perfectly, IMO.) I had their model IS-4041 four-mode stereo system for 17 years, not to mention two Zenith 13-inch color TVs and a Zenith 19-inch color set; I still have the 19-inch set which still works, although it is presently gathering dust in my bedroom since the DTV changeover in 2008. I will not be using it again, since I would need to rent a cable box from Spectrum, the TV provider here, and I simply do not want to spend any more money for TV for any reason unless I need to replace my present 32-inch Insignia HDTV some day. I have what Spectrum refers to as "streaming" video service, which does not use or require a box; this suits me to a T since I am a senior citizen on a fixed income.

Hey Jeff, thank you! I was pretty excited and much surprised I was able to figure that out and actually get the color working. I was starting to loose hope lol. I am no where near an expert or even know what I am doing. Just trying to learn. I have always loved these older televisions. The picture on this set has been amazing though. This set has been a tough ride for me, its breaking faster than I can keep her going lol. I am hoping it just working the kinks out since its been sitting for so long. The latest problem I just ran into is, I believe the trippler has failed. Took a lot of digging, but I believe I found one and its being shipped today and on its way to me.

I just had some amazing luck though, I was out on a job site today and the customer had several old TVs he was just going to throw away. So I made a deal with him and one of the sets is the table top version of my console! lol A Chromacolor II, though I believe its a bit ealier of a set than 75. Haven't been able to find a date on it yet. The lay out is almost exactly like mine, however all the module cards look to be older like maybe the original versions or something. I powered it up and it does work, but it has some problems to work out with the screen controls it seems. Also I dont think its had the 4 lead capacitor modification done to it yet. I need to figure that out and if not how to do it. I will probably check into that here soon once I get the sams in for it. Also another set I bought from him was I believe an early color RCA CTC-9 or something around that model. Its a bit rough though, been in an attic of a barn, going to try to totally get that thing going and looking good again! I will probably go and pick that up when its a bit nicer out.

if you have youtube and want to follow along with my progress on these sets, here is part 3 on the Zenith console set, where I got the color working. I will probably do some for the tabletop version as well.

https://youtu.be/kjNz2cdExmw

Yeah its really sad that Zenith left Chicago and outsourced out of the country. I believe it was around 1978 or 1979 when they closed up the Sioux City Iowa plant not too far from me here and moved the production over seas. Sadly the start of the decline I think.

Too bad you dont have a way to get a over the air digital converter box to use on your old TVs. Not sure if you are able to get up an antenna or not or close enough to broadcast stations without having an outdoor one. But them old Zenith dtv boxes show up on facebook marketplace and ebay for relatively cheap and once past the original purchase, there isn't any more cost involved and youll be able to use your old sets again.

Welp 73's there Jeff

[radiotvnut]

The model or chassis number can tell you the model year. E is '74, F is '75, G is '76, H is '77, J is '78, K is '79, and L is '80. If it still has the white safety capacitor in it, don't run it until it is changed to the orange capacitor. 1974 was the first year for the vertical chassis CC2 models.

[Mangie]

Originally Posted by radiotvnut

The model or chassis number can tell you the model year. E is '74, F is '75, G is '76, H is '77, J is '78, K is '79, and L is '80. If it still has the white safety capacitor in it, don't run it until it is changed to the orange capacitor. 1974 was the first year for the vertical chassis CC2 models.

Very awesome info! I have been having a hard time figuring out what year both my Console and tabletop sets were. The console is a 23GC45 so that is actually a 1976 not 1975 then.

The console has the orange updated cap, however the tabletop does not. Ive been bad and ran that set a bit already.