[Munchkin]

I've been hassling with a Sony KLV37S400. Turns on fine, then turns off at random times with a loud pop on speakers. I nearly had a probe slip the first time it shut down on me due to the 'pop' sound being so loud. I have run through the inverter board even though a hard shut down like this didn't seem to point to it being the fault. All levels on the G2D board (DPS-250AP-34) were ok, although ripple levels were concerning. electrolytics all OK, discrete semiconductors seem fine nothing runs hot at all. My only concern was the duty cycle on the MIP2H2 seemed a little high and wave form seemed typical of a failed snubber or lack thereof. Other concern was when probing the reference pin on L431 (1.25V version) supply relay would click on/off like a car indicator. and levels at this feedback fluctuated drastically, dipping lower and lower in incriments of .01V till shut down. At times I would observe a sound that could only be described as fluttering coming from PFC stage. \r\nI had a probe slip late one night and blew fets on the main supply including the controller. being a DELTA unit with proprietary component numbers My best guess based on topology was a L6598. also replaced the PFC control with L6562. Worked again with same symptoms. only IC I couldn't figure was a ST micro device in SOP8 marking is DAS001.
I have run through the input board audio stages as well, after plugging in a GP 1-875-582-12 (swapped pins on input board connector and changed backlight inverter connector) and for the first time getting the unit to go into self diagnosis indicating 8 flashes.
This unit has just been adding insult to injury and it is now personal. I have a satcoms development background and smps design for maritime applications was were i picked up extensive experience.....but this one has me stumped!