Magnavox 42mf231d/37 power supply question

[freakaftr8]

Hey guys Just picked up another one of these with same problems as the last power supply. Same model. This one now I have no control over the vscan varistor. It's stuck at -173 vdc. It should be around -190v. I replaces the shunt regulator and optocoupler for good measure in that circuit still no change. Any ideas? I replaced shorted ic561 zd505 f501 from imminent doom

[StellarTV]

I had this happen on a different model once. Adjusting the pot in an attempt to bring the voltage back in spec resulted in the offending leaky transistor on a neighboring board exploding, which left my ears ringing for over an hour. Is your problem with the load, and not the supply?

[CoogarXR]

This may or may not help, but I know first hand that TV has the timebomb YSUS/buffer combo. They always die. One buffer chip shorts, it takes the whole YSUS board with it.

[freakaftr8]

Yes I know about the timebomb ysus/buffers. I have worked on about ten of these sets rebuilding the ysus mosfets and shorted diodes and replacing shorted buffer ic's.

And in turn I have had only one besides this one cause damage to the power supply as it grenades up the chain of command. This tv though the buffers and ysus were ok oddly. I cannot be sure though that someone before I picked it up had already replaced the bad buffers and ysus and when it didnt work, gave up. I can only assume. But as to Justins comment, yes I have replaced the shunt transistor for the pot control. Still no change. It seems that I am getting 205v to the primary side of the vscan transformer, just nothing out. Its just mind boggling that the ysus is producing enough voltage by itself to operate the vscan circuit on the back side. Is this voltage bleed?
Still even with this and ysus disconnected, all voltages come up on power supply except vscan, there is a possibility of me overlooking something on the ysus that caused the power supply to blow.