Electronics → Phillips 46PFL5705D/F7 won't turn on (help diagnosing)

Hi Guys,

I've had luck diagnosing tv's here before so I thought I'd enlist your guys help again!

I have a Philllips 46PFL5705D/F7 that will not turn on. The power led (logo led) will blink 25 times before a short gap, and then start the 25 blink cycle again. Pressing the power button elicits no response.

Here is where I'm at (more details below, see pics as well):

1. Tested for voltages at the main board
2. Tested voltages at the inverter board
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1 - Main board connector (tested at the main board side of connector).

Pin 1 - 12.48V
Pin 2 - 12.48V
Pin 3 - 12.48V
Pin 4 - 12.48V
Pin 5 - 0V
Pin 6 - 0V
Pin 7 - 0V
Pin 8 - 0V
Pin 9 - 5.38V
Pin 10 - 0V
Pin 11 - 0V
Pin 12 - 3.08V
Pin 13 - NC
Pin 14 - 0V

The 5.38V is a little off, as well as the 3.08V, but my guess is that's not the issue (could be wrong).

2 - Inverter Connector 1 (14 pin w/ controls)

Pin 1-5 - 25.4V
Pin 6-10 - 0V
Pin 11-14 (controls) - 0V

3 - Inverter Connector 2 (10 pin)

Pin 1-5 - 25.4V
Pin 6-10 - 0V

Clearly 25.4V is quite a bit higher than 24V. But, I don't know the inverters' voltage tolerances (could be that 25.4V is fine).

I'm not sure where to go from here. I can take more pictures if necessary and test for voltages at any point.

Any advice as to how to further diagnose?

Thanks in advance for any help.

-Ian

No air gap I'm pretty sure. Also I don't think there was ever a heat sink, none that I'm aware of at least. See pics.

I am guessing the backlighting (LED array?) is NOT turning on either. Have you checked for shorts and opens?

Just a wild guess for following signals:

PROTECT3 : some sort of error indication
PSON : which locks the main power supply ???
BL_SW : and maybe also the backlights ?

BL_ADJ1/2 : backlight level adjustment