CTC140 (RCA Dimensia) Rapid on/off & No Sound

[olePigeon]

Hello. I have a nice RCA Dimensia console television with a CTC140 chassis. I picked this beauty up free off Craigslist about 6 or 7 years ago. It had a few reoccurring issues that I was unable to diagnose and fix since the day I got it, but unfortunately it's now progressed to rapidly turning on/off. I'm afraid to leave it on in this condition to try to diagnose it for fear of damaging it further. These were the original issues:

1. When you first power it on, the sound would pop and hiss on the right channel only. After the TV warmed up, the popping would go away, but there's no audio on the right channel (this may or may not be related to the main issue.)

2. The main issue is that the CRT would randomly shut off for a brief moment, then come back up. On rare occasions the color would be distorted. Turning on/off the set fixed it.

Well, it had its last fritz, and now it's rapidly turning on/off. I can not find a schematic that isn't behind a paywall and only have the two service documents from inside the set.

I did find 4 1uf 50v capacitors that were all completely dead. I replaced those and tested the rest, but they were surprising all good. I had a brief moment of joy cuz the TV set cam back up when I plugged it back in, but zero audio. There was a light popping sound coming from somewhere, but I couldn't find it. Then a day later when I was going to sit down to troubleshoot the audio, the tube had reverted back to rapid on/off. I'm hoping the flyback isn't bad, although if I could definitively know it was the flyback, then I have no problems replacing it. Looks like a replacement flyback is only $20.

I tested the Horizontal transistor with my cheap component tester it tests good (although I don't know if it'd know if it was leaking or not.) I have yet to test the resistor near the transistor that can short and go bad, so I really need to do that. Cuz if that's shorted, then it's likely the transistor is going as well.

My deep dive in Google searching for (and failing to find) the schematic seems to indicate the most common point of failure are the diodes. I've tested all of the relevant diodes, and they test fine with my cheap tester. I would be OK with just shotgun replacing all the diodes anyway, but without the schematic with the parts list, I don't know the ratings for any of them.

Could use any help. Thanks.