Need Help with 1978 Zenith Chomacolor II
 

Hey there,

Well I cannot seem to figure this one out. 17" Chromacolor 2 with rotary tuners, circa late 1978.

The left side of the picture is dimmer than the right, I may be dumb and should know what this is, but any ideas? Picture focus, color and contrast and black level all operate as they should..

This is a module style chassis...

I don't know where it is physically located in this particular chassis; but, look for a 10 uf, 350 volt (or a value close to it) electrolytic cap. This is the value that was used in the later sets and was a common failure. Your cap will probably be located on the flat part of the chassis where all the power supply components are.

If you'll post the chassis number; I'll see if I have a Sams Photofact and I'll tell you where the cap is physically located and it's exact value. This cap is in the 200 volt supply to the video output circuit. I've seen that cap defective in the later System 3 chassis and cause the same problem you are having.

Agreed. I had the same thing on a SYS3 set. Capt'n Moody fixed it.

Very weird problem.

You guys are awesome, ill get into it later this week and let you know, ill look for that cap too! Thanks!

If yours has a board on the CRT socket, the cap may be on there. If not, it may be on the 9-88 module. On the later sets (Sys III,) it was on the main board near the FBT.

Charles

Found it, it's on the chassis bottom oppisite of the FBT. Ill change it out in the next few days and let you guys know how it does! Oh yeah the chassis no is 17KC55 and tv model no K1720W

If I can find that manual, I'll take a look. The K line is about the very last Chro II chassis. They had some weird things added, and some special modules for the smaller 17" cabinets. That could affect where that cap is located. I didn't think it was on the bottom chassis piece though.

Charles