Although the component values do not match the schematic the layout looks identical.
Budm was quite correct that the power supply should power up when disconnected from the main board i.e the 24V and 12V should be available at the connector without the need to provide any other signal. Just like Budm I cannot see how the supplies come up when pins 1& 2 are lifted.
I have run a simulation of the circuit and the opto led definately needs to be switched on for Vcc to become available.
With the power supply still disconnected from the main board and the opto in place what VCC_Main, +12VCC and VCC do you have. Pin1 of U201 looks like it's not quite soldered back in place.
VCC_Main at R246 - around 9v goes up to about 16v and drops
+12VCC at R270/1 - goes up to about 12v but drops
VCC at D200 - around 9v, goes up and down to about 12-14v
Swapped it over and got a steady 24v on CN4.
Plugged the psu back up into the tv and voltages back to fluctuating, even with the board isolated from main and backlights.
Not getting 400v across C105 either just sits at 340v.
Could it just be unlucky this one has gone faulty (it is a used part) or what could be 'blowing' them?
With the mainboard disconnected from the power supply do you now have 390ish volts across C105 and the 12V & 24V supply. If the answer is yes then you may well have a mainboard problem supplying ST_BY voltage to the power supply.
Yh. I measured a steady 12v and 24v on CN4 then decided to plug it all up. Still.no sign of life then measured volts again to find the fluctuating 12 and 24v.
Disconnected the main to find voltages still fluctuating and no 400v on c105 whereas before it was at least ramping up to 400v then dropping back to 336v.
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