CTC-31 Color Problems

[bgadow]

I flipped a coin last week over whether to post this on antiqueradios or here; no response there so here I am.

This tv had been in storage for the past 5 or 6 years; when I pulled it out the other day I decided it had been too long since I had worked on a set & this should be the one. When I had last used the tv the picture was just tired looking, poor reception, poor color, poor contrast, etc. I powered it up last week & had a weak picture with messed up color. I kind of jumped the gun & starting swapping 6GH8's all around. (this set is my payback for posting last week that 6GH8's never give me any trouble!) Actually I found most of the trouble was in the agc and after adjusting that & the gray scale I had a very good bw picture. But where did the color go? Since then I have swapped the crystal & the color killer transistor; replaced the filter cap that feeds the circuit along with a burnt resistor in the power supply; tested every 6GH8 in the set & on the shelf & put the best of the best in the set; adjusted the coils per the directions in Sams. I did finally get color back with the color bar generator hooked up. The trouble is that I cannot get it to stay put. Well, it will stand still but tweaking the tint control will send the color bars spinning in one direction or the other. I finally gave up for the night & decided to just hook up the cable so I could at least see a color picture with this set-when I connected it I had a dark, overloaded raster. The agc was too far out, turning it back to get a picture causes the color to go away.

One odd thing that happened: while probing one of the demodulators there was a flash of spark and a loud zzzappp!!! in the area of the 3.58 oscillator. I am almost certain this had nothing to do with my measuring the voltage several inches away. I could see no obvious damage & nothing seems to have changed. I did notice that coil A19 (going by memory here) has no effect on the voltage when I am doing the alignment-I've done no other check & wonder if it could be bad?


I look forward to bringing this set back. Its a remote set, a lot cleaner inside than I remembered. This is the tv I bought from a guy in the mid-90s who was doing bait & switch: come in to see the $5 color tv he has for sale and walk out with the $50 Sanyo instead of this old beast.