Chromacolor Flower power!

[zenithfan1]

I bought this set from Mike aka radotvnut out in NJ. I've had it awhile and have only "tinkered" with it a few times. It is a '72 Zenith Chromacolor 18 in. The reason I dubbed it the "Flower power" is because of the flowers that someone painted on it years ago. I was going to remove them but a close look told me someone spent quite a bit of time painting them so I left it that way. Mike told me that an old lady who was an artist used to own the set and those flowers have been there since the '70s when she owned it. My 5 year old daughter fell in love with the flowers so I gave the set to her, I just have to fix it. I am getting closer. The thing was well packed but as usual, the shipper threw the thing around causing a piece to break off of the cabinet, that was glued back on with industrial strength super glue that I get from work {you can order it through Kimball Midwest} There were three bad tubes IIRC, a 9MN8, 15MF8 and a 6U10. I also replaced the high voltage tube socket and cup with a NOS one from Chesters Electronics. When I first powered it up I could hear the HV hissing, I took the can apart and found that it was ready to burn my house down, it was arcing all over the HV rect. tube and melting the plastic HV cup. The HV tube cap was also badly melted, corroded and scorched. I replaced it by stealing the one from the fly from my '65 Admiral roundie as I just replaced the fly in it, I'm glad I didn't throw it out yet! Also replaced was a 300 MFD@200VDC cap and two NTE 116 diodes that were attached to the positive side of that 300MFD cap. The thing is working now but still has issues, I tested the CRT with a Sencore CR70 it passed all of the shorts,emissions and color tracking tests, on the life test the needle did not drop at all. I can rule that out as far as the brightness problem. I think it lies somewhere in the chroma or brightness curcuits. When the brightness is up all the way it is possible to watch it but is real dark in the low light areas of the screen blacking out the darker details of the picture. The brightness is only acceptable when the color is turned to 3/4 of the way. when you turn the color down, the brightness goes with it. It seems like a leaky cap in that area to me but I could be wrong. I'll keep messing with it, maybe someone here knows what's wrong. There is also one more thing, after I rebuilt the HV section, I still only get 19.5 KV when it calls for 21.5 with the setup switch in the set up position and contrast and brightness all the way down. It is much better than it was, it read 18KV before the repairs. I was a little disappointed when the voltage didn't come up as it should. I know this can cause brightness/focus issues as well. Any tips would be appreciated.



The speaker was also broken from it's mount.


Glued in nicely.


I tried to remove the carbon tracking but the cup was too badly burned.

The old cap and diodes, the diodes had become red hot. They were covered in soot.

I picked this stuff right off the shelf in Chesters.

[zenith2134]

Nice work with your repairs! The set looks good. As you mentioned, the ~2kV deficiency might be all thats wrong with the set as far as the brightness issue is concerned. Have no idea about the color control affecting the brightness, though.

I like this Chromacolor alot, it has a lot of class.

[sampson159]

those are some of the best sets ever.nothing beats a zenith.great score mark! put it beside that ctc9-you now,that 9 you got at the convention!! i am still waiting.lol

[zenithfan1]

Thanks for the compliments! Here is another pic of the HV tube cap, there was quite a light show going on in there up until the other day! The "new" cap is beside it.

[roundscreen]

See the two white caps marked 648. Replace them with some orange drops of the same value. That may be why the high voltage is a little low. Also I seen that type of cap blow it's gutz in the 25" zenith Chromacolor sets. Even if they check good get rid of them.
I think it is neat you are leaving the flowers on it. It is a part of American history
Ed

[Keefla]

Originally Posted by roundscreen

I think it is neat you are leaving the flowers on it. It is a part of American history
Ed

I agree, actually my sylvania set that i recently posted about (and subsequently was walked through a successfull diag and repair ) has quite a few stickers on its cabinet collected over the last 10 years ive owned it. kindof like a scrapbook of sorts. kinda odd i know but i think its cool, people ask me about it and i give the breif rundown of some of the more important ones.

[Findm-Keepm]

Concur with replacing the white ceramic time bombs - but if they don't fix it, try the VDR's in the HV adjust circuit - usually below the the Horiz output tube. What's the chassis? Some have one, others have two. DC chassis, perhaps?

Cheers,

[mr_fixer]

I also like the custom paint job, It is very tasteful. It must have been a loved possession for the owner to take the time to decorate it. Logan

[WISCOJIM]

Originally Posted by zenithfan1

I also replaced the high voltage tube socket and cup with a NOS one from Chesters Electronics.

Thank God for places like Chesters! I wonder how many places like that still exist?

[drh4683]

I agree with Brian, definitly check the VDR's. Im taking a guess that this is a 14CC16 since it has AFC and you say its a '72. These are nice sets to work on, pull the back off and all the parts are accessable. BTW, your repairs look very clean and professional. The only way to do it! Is chester electronics a local parts distributor in WI?

[Kiwick]

Originally Posted by zenithfan1

The speaker was also broken from it's mount.

Was the speaker cone damaged? the surround appears to be torn in this pic

[radotvguy]

Glad to see the zenith got a good home . The old woman who owned that set was a artist and painted things on everything like end tables , furniture and the tv . I watched that tv for years before it was put into storage .

[Bill R]

Looks like and sounds like from your description that you may have not enough video drive. Pictures look like the color information is getting through, but you have little or no video. If you turn the color all the way down there is very little or no video left? I would start looking around the delay line, and video amplifier/driver circuits. The HV is a little low, but you should still have a better picture. There may be some out of tolerance high value resistors in the HV circuit, or as suggested maybe some leaky caps still holding the HV down.

Bill R

[drh4683]

Definitly check the 121-587 video driver transistor. Ive had leakers and cause low Y on chassis from the 20Y1C38 up to 20CC50's. Transistors are usually good on zeniths, but the video drivers have had their fair share of failures. If you sub out the 121-587 with and NTE type, I think the pin out is different than the original, so dont plug it in like the original or you'll have more problems.

[JB5pro]

Is that decopage? I usually like everything to be as it was from the factory but I accept exceptions occassionally if there is a good reason. That cat seems to know something is not right or he likes it too. If it was done when the set was new I would think more of it than if it was done in recent times. That is a pretty cool set in general. That broken corner piece can be nicely "welded" back from underneath with a light soldering seam applied while pressing the crack closed. Then maybe a JB weld application to the underside after a scratching or sanding. I am not aware of epoxy's that may have been offered from electronic supply places but I suspect there are such that are maybe better than JB weld. Hopefully all this was not already written here.