JVC 56P575 no power

[rca2000]

171 volts DC on that big cap-with no load...sounds about right. This sounds like your power supply is NOT running at all. If you did not see some appricable voltage on those diodes--"the side connected to those capacitors--NOT the transformer side..cathode of most..anode of a few--),with the black probe to cold ground...this means the SMPS is not runni9ng at all--since if it was in overcurrent mode...from a shorted load...it would either be squealing or chirping..but with NO noise...it is just DEAD.

SO...NOW.. I need a better look behind the transformer-- that big heat sink...to see what sort of switch mode driver you have...whether it is a chip or a MOSFET driven by a small chip off of it. I THINK I see an optocoupler--those OFTEN go bad--and stop all oscillation of the SMPS... I ALSO... need to see the BOTTOM of this board...especially the area near that transfoemer...