ctc-97: Trying to diagnose tuner ghosting

[zenith2134]

I've been having a weirdo problem with my 1980 RCA which has me stumped. After the set warms up the tuner ghosts pretty severely to the point that text on the screen looks like its off-convergence (not a convergence issue though...).

I have the channel-lock feature set to block out all channels except 03 since I run the TV with DTV cable. Interesting thing is that if I press channel up or down, the ghosting goes away for a few minutes. Therefore, if I attempt to change channel with remote or pushbutton, it just flashes quickly and returns to channel 3. This is normal, but I'm wondering if maybe the set doesn't like being stuck on channel 3 all the time? I already replaced the filter capacitor, 3 b+ capacitors and a few resistors on the video output module. It would be a shame to scrap the set because of this silly problem IMO. I doubt tuner modules are available however. Already ran a search on google and found a similar condition with the ctc97, and the diagnosis was to resolder all grounds, which I did.

To be honest, I have very limited experience with digital tuners, especially early ones like this one. Is there something to clean out or anything mechanical inside the tuning box?