Have a u5000 im working on had some power supply issues fixed those it passed the light bulb test fine, b+ was around 125v dc which should be fine, oddly hooked up to the tube it reads about the same even thought the high voltage never kicks on. I have tested all the usual culprits HOT even thought it makes no ticking i hear absolutely nothing, r760, r765, r728 even out of circuit, q703, q708 etc etc pretty much the entire horizontal side compared with a working u5000 and have found not a single thing, all i have noticed is q703 is getting really hot and it has the heat sink mod on it, i know it gets hot already but i think way hotter than normal. I went to test it out of circuit and the original one the legs literally fell off so I replaced it and the new one still gets really hot and no high voltage so i dont let it run for long. Swapped the LA chip since it already had a socket installed and it was easy still nothing. Tested continuity everywhere found nothing out of the order. It also has a new cap kit installed so that should not be in question and double checked my work, i did the cap kit to rule it out actually.
Any thoughts?
I think my only next move is to either change the HOT even though out of circuit it test fine and is an 86 not an 88 or to replace the flyback, im a bit suspicious of it anyway because its the bleeder box type. But im not sure if either of those could cause q703 to burn up.
Or possible a weird issue like a ceramic cap or poly cap even though i inspected all those and tested for shorts and found nothing.