Philips 47pfl8404h/12 no power on

[Nawual]

Hello,I have this TV that does not turn on, only the blue LED flashes. I have measured the voltages that come out of the PSU and I have 3.5 in power-on and 3.3v in VSB, you can see it in the photo.But in the others only 0v.

[Nawual]

Re: Philips 47pfl8404h/12 no power on

I have removed the PSU from the TV, and I have connected PS-ON with the last 3.3v pin through a 1M resistor and I still have no tension on the 12 and 24v pins.

[budm]

Re: Philips 47pfl8404h/12 no power on

Can we see the pictures of the whole top view and bottom view?
We also need the pictures of the whole back side of the TV showing all boards so we can see how they are connected together.
The resistor should be between 470 ~ 1000 Ohms range, 1M is way too high for it,

[Nawual]

Re: Philips 47pfl8404h/12 no power on

Hi Budm,sorry, the resistor is 1000oh.
I have found the scheme of this PSU and I have realized that the transistors that go to the 3.3v are PNP, then it is inverse. So I have joined the PS-ON pin with the SGND1 that is next to it. And I have measured the 12v and 24v pins and bingo!, I have all the tensions. Now I have to find out why the PSU is not activated.

[budm]

Re: Philips 47pfl8404h/12 no power on

So it is active LOW for the PS-ON, I should have caught that when I look at you picture in post one with 3.5VDC is already present without the resistor.
At this point the main board is not pulling the PS-ON line to low, so next place to check will be the main board.
Can you please also upload the diagram of the power supply so it will help other people in the future?

[Nawual]

Re: Philips 47pfl8404h/12 no power on

Yes, it was stupid to put up the resistance since there were 3.3v. I go up the diagram for those who may need it. I will continue with the motherboard, I'll tell you.