Model # 50UX57B Chassis # AP83R, was worked on elsewhere! Both convergence IC's were replaced, & I found D910, & D911 12 volt zeners in the SMPS shorted. E995, & 996 fuses were replaced. I replaced the SMPS IC regulator. All the pico fuses, & fusible resistors are ok. Nothing looks overheated. Nothing else is bad, that I can find! Nothing is dragging down the secondary of the SMPS, but it just won't oscillate! All the capacitors in the secondary, & primary of the SMPS check out fine! Anyone see this type of failure, in this unit? Thanks, Dani.