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  #1  
Old 02-02-2019, 06:06 PM
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maxm maxm is offline
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1977 Zenith Chromacolor II Space Command

This set is a recent estate sale find. It was in a finished basement and is in pretty nice condition. It included the remote control, though the remote will need a new battery connector because of corrosion. Model SJ1939W, chassis 19JC60Z.

After running for about 30 seconds the picture began to get washed out, then the black electrolytic capacitor on the horizontal chassis in the photo (10uF, 350V) failed by venting a cloud of smoke. Should I change the capacitor and try again, or would this sudden failure be a sign of another problem?

Also, the large oil capacitor on the chassis is starting to leak and I would like to replace it (3.5uF, 440V AC). Would one like this work instead?

https://www.ebay.com/itm/401430955618
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Old 02-02-2019, 06:07 PM
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Photo of failed capacitor.
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  #3  
Old 02-03-2019, 05:07 AM
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That's a nice find, Max. I would replace the lytic and go from there. However, also replace that oil filled cap too before going any further. You should replace that one with another oil type which can still be found in the same physical size. Be extremely careful when handling the old leaky cap. Those oil filled caps before 1979 contained PCB's which you don't want to touch as that stuff is bad news to your health. Absorption through skin contact is what you want to avoid, so be sure to wear gloves when handling and cleaning up any residual that may have leaked in the cabinet.

The oval oil caps can be found at McMaster Carr.

I believe MMC part number 7602K23 will work (it's rated at 3.8-4.2 uF), but verify the can dimensions as it should clip onto the chassis just like the original with a retaining clip I believe. The original 3.5 uF is hard to find new now, so the 3.8/4.2 would be your best bet.

https://www.mcmaster.com/capacitors



Grainger also has the oval caps. The Dayton 4 uF would also work:

https://www.grainger.com/search?sear...oval+capacitor


The electronics supply houses like Mouser don't appear to carry a wide range of these caps, so the industrial suppliers seem to be the best answer.



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Last edited by drh4683; 02-03-2019 at 05:49 AM.
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  #4  
Old 02-03-2019, 10:48 AM
zeno zeno is offline
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The cap is probably the filter for the 200 volt supply. They went
left & right on ALL brands. change to a 450 V & higher temp.
they cause all sorts of poor pix problems. Never seen anything blow
one out but it is possable....

Doug covered the oil cap well. You can also get one from almost any
Zenith solid state up to apx 1979. Other brands used it too on
top of line chassii.
If cap shorts set will hum loud then pop breaker. If it opens the
pix will "breath" or pulsate. Rarely went in old days but common
now.

BTW your set uses an EFL CRT. Not many seen here until later years.
In J line it came in 17 & 19" only on high end sets.

73 Zeno
LFOD !
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Old 02-03-2019, 05:57 PM
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Thanks for the capacitor information. I'll order a new oil cap. Yes, the original one is marked on the can that it has PCBs, so it is probably good to get rid of it.

This set was in an older higher-end home and looked like it was used as the TV for their basement rec room. It appears to have seen little use. There wasn't much dust in the HV area and the remote buttons and controls on the set have no wear from use.
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Old 02-04-2019, 05:39 AM
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I've had three types of sets that use a ferroresonant power supply with a 3.5uF oil-filled cap; Zenith of course, Sylvania and Electrohome. When I wanted to replace the run cap in the latter I was told I couldn't use a 4uF cap (I ended up getting a NOS 3.5 from a member who is no longer active here). Now I'm wondering if 3.5uF was a common value for run caps when these sets were made and 4uF was practically non-existent, basically the opposite of what we have today. Can someone clear this up for me?

By the way, nice score on the TV. The unusual feature set is pretty cool.
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  #7  
Old 02-06-2019, 04:10 PM
mrjukebox160 mrjukebox160 is offline
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https://www.tedss.com/2020038517
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  #8  
Old 02-08-2019, 08:02 AM
zeno zeno is offline
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Funny how that York cap has the Zenith part number on it ! Must
be NOS.

Quote:
Originally Posted by mrjukebox160 View Post
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Old 02-10-2019, 01:27 PM
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I installed the new caps and the set worked well for about 5 minutes. Then the picture suddenly changed to a blank bright white. When the electrolytic cap failed the first time, the picture was gradually fading to a blank white. Nothing smoking this time.
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Old 02-10-2019, 06:16 PM
zeno zeno is offline
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Check the DC voltage at the positive of the cap. Should be 200-225 VDC.
The lower it is the brighter the pix will get. I will pull the manual
tomorrow, I should have it.
Also you can check the resistor packages on the 9-88-? and
the 9-121 CRT board for cold joints. Very common in the olden days.
They are the long flat B&W ceramic things.

73 Zeno
LFOD !
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Old 02-11-2019, 09:42 PM
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I checked the CRT board and 9-88-06 and both had bad joints on the resistor packages. I resoldered those and got the same result (see attached). The voltage on that cap is 235V when first powered on, dropping to 183V shortly after.

Thanks for the help. I looks like my library has a service manual and probably the Sams, I have to go there sometime to look.
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  #12  
Old 02-12-2019, 08:20 AM
zeno zeno is offline
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OK fine
Sounds like the video is loading down the source. You will probably
find the cathodes very low. If G2 is too high it will do it to. Move the
G2 range jumper ( yellow wire ? ) & see if it fixes it. I do have the
Sams if you need more help.

good luck
Zeno
LFOD !
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