UN55D6000 - Multiple issues, now no standby light

[fuxxy]

UN55D6000 I've posted about before.

Initially had bad backlights, of which both entire strips were replaced.
Then TV started not staying off. Every poweroff command was recognized, TV would power off then power right back on, even with nothing attached.

Now, no output at all. No red Power LED, No response to remote. No clicking or coil whine.

From other threads, tested various outputs on the PSU. Noticed that when the mainboard was unplugged, the backlights would turn on.

Backlight Connector CNL802:
Logic board unplugged:
pin 1 = 335V
pin 3 = 167.4V
pin 5 = 167.4V
pin 7 = 1.113V
pin 9 = .603V
pin 10 = 0.0V

Main filter cap CP806:
Logic Board unplugged: 330v DC
Logic Board plugged: 169.5v DC

Mainboard Connector at PSU (mainboard unplugged)

2 (n/c)      | 1 (n/c)
4 (EPWM) 3.19v   | 3 (B13V)12.72v
6 (n/c)      | 5 (B13V)12.7v
8 (BLU_ON) 2.98v  | 7 (Vamp)16.83v
10 (GND) 0v    | 9 (Vamp) 16.83v
12 (GND) 0v    | 11 (GND)0v
14 (A5V) 5.33v   | 13 (B5V)5.33v
16 (PS-ON) 3.33v  | 15 (B5V)5.33v

After having the logic board unplugged for the hour or so it took to take measurements, I plugged the logic board back in and the TV turned on.

Do you guys share my assumption? Power board most likely good. Backlights most likely good. Logic board is suspect.

Are there any component level diagnosis I can do for the logic board?

[Davi.p]

Re: UN55D6000 - Multiple issues, now no standby light

You must rewrite the Weltrend MCU..