This TV had no power at all and no standby voltage.  There is a repair kit available for the power supply board DPS-411AP-1 at Shopjimmy.   There is a service manual online but no schematic for the power supply board.

Advice on badcaps suggested looking at the circuitry around IC901 (ICE3BS02G) which generates standby voltage as a separate circuit from the incoming AC.  Components to check include F2 (small red fuse),  R929, R903 and Q905.  R929 was open and I replaced it with a 2.2ohm 1/4 W fusible resistor.  It blew when I plugged it in and there was also visible damage on IC901.  I tested Q905 on my ESR tester and it was not shorted.

ICE3BS02G is obsolete but the manufacturer lists ICE3BS03LJG as a replacement and this part was available at Digikey (part #ICE3BS03LJGXUMA1CT-ND).  I also ordered a 1 ohm fusible resistor to replace R929 (Digikey part #1.00DCCT-ND).

When the parts came in, it was difficult to find the pin 1 marking on the IC.  Taking a pic of it, you can see it on the bottom left with the markings upright.

With the two parts replaced, the TV powered up.