This TV was dead with no standby light and no power. A service manual is available for download here.
The power supply board has jumpers as test points. I measured 20VDC P-ON+21V and 0V on AMP+13V. AMP+13V provides power to the main board. There is a FET which could short and blow a fuse but the 20VDC reading indicates the fuse is ok. Checking the resistance of AMP+13V to GND with the board alone, I measured a short.
In the service manual, there is a flowchart for this line. AMP+13V is not output. No-> Check D653, D655, C654, C655, C668 and their periphery circuit. Repair it if defective.
Pulled off C654 and C655 and they both tested good. I lifted one leg of both of the diodes and D653 was shorted. The part number is SB3A0BH which is a 100V, 3A Schottky diode. Equivalent substitute at Digikey is SB3100 (641-1418-1-ND).
I replaced both diodes and TV powered up. Luckily, there was no damage to other parts when the diode shorted.