Check C9081. Just about every a1990 I have had had a shorted C9081. You can use schematics and boardview for 820-0141.

So did replacing the UR500 solve the problem?...

Re: philips 55pft5201/79 no power

Did you end up getting it fixed?

Here they are in case anybody else wants them.
Included is:

schematic
Boardview...

Re: Dead 820-01598 - voltages present but no boot

I have the exact same issue. All large coils have correct voltage except L7702 (PPVCCEDRAM_S0_REG_R). There is no short on that rail. 1.8v on all_sys_pwrgd. I replaced Q7702 and U7710 with no change.

Re: Eeprom dump thread!

Sorry didn't make notes on board number....

Re: LG 55LA7400-UD Dark on right side

I know this thread is 2.5years old, but just want to add to it to help anyone else landing here. I had the same problem with this set, except mine was a little way in from the right hand side. It would work fine initially, but after a minute or so the backlight would partially go out. I got my hands on a cracked screen 55la6620 for $20, and used the led strip to replace mine, that fixed the problem. It is an single strip edge lit (from the bottom). Big job to swap them, ALOT of screws, but not exactly hard. Upon testing the individual leds on...