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