Ugh. I HATE these Vestel PSUs. I've been trying to fix this one more as a project than anything else, because I feel like buying a new one would be giving up. It seems every time I fix something 10 more issues rear their head.
Anyway: After fixing lots of little things... such as the 15n/630V caps, the caps around the PWM controller, the caps around the LM317T, the caps around the standby controller, a few cold joints and finally getting a decent PFC voltage (388V), I put the unit down to rest for a few days. I plugged it into the TV today, and find the 5V rail is bouncing from 0V to 5.06V every second, as are the other rails. Tested it with a scope, it seems like it switches on and then switches off every second. The LED on the front blinks in time with this bouncing. I can hear a buzzing sound when the LED is lit, and nothing when it is not lit.
I have a junk 17PW20 with a dud PFC inductor (just replaced with wire as a temporary standby fix) which only gives standby power and that voltage is stable. So why isn't this one?
Any insight would be much appreciated, would be great to get this TV working before Xmas.