Philips PSU (715G7350-P01-000-002S) No stand by light (0V)

[blablaro]

Hi all,

This is the source from a Philips TV 43PUH6101 that suddenly stopped.
I know it's the source since I have ~ 0 volts on outputs 12VA/16VA, 12V/16V, +3.5/+5V

For the latest weeks I've been trying to figure out the problem with this. I've ordered all kind of mosfets, a capacity meter and other things to try to figure out the issue with this PSU. My wife thinks I'm crazi but I want to repair it

Initially, when I started the testing with the multimeter on diode mode (220 V on):
- discovered that was Q9101 shorted (or I shorted it)
- R9109 blew out
- both replaced
- replaced main fuse: F9902

On the back:
- D9105 was shorted - replaced
- just replaced the 8 pin SMD: U8601 that I read that usually gets broken.

Tested different diodes, mosfets, everything seems to be fine. Nothing else seems smoked, blown.

On the cold side everything everywhere I test voltage 0 so I believe it's something on the hot side.

On the hot side, the big brown capacitors have 320V and measuring with the - on the capacitor I measure 320 on D(drains) of all the big mosfets (on the hot side).

If somebody can help / guide through on what to check next, please let me know (I have a multimeter and a capacity meter: bside esr02pro)

Thank you for reading and the possible help!
Adrian

[nomoresonys]

How bout a picture of the whole back as to see how everything is connected.

[blablaro]

Please see the attached.

[nomoresonys]

I assume you checked D8609.

[lotas]

When a MOSFET breaks down, it often takes diodes, zener diodes and PWM with it. Check and replace.

[nomoresonys]

Sometimes they can be tough to figure out, I'm seeing these powerboards for about 20 dollars on ebay etc. At that price what I would do is get a replacement, you want to match up the numbers on the white sticker on the powerboard.

[blablaro]

I assume you checked D8609.

-> Yes, yesterday I removed a side from the circuit to test it because of the 2 rezistors (22 and 47 ohms) connected to the same side I could read 069 or 070 (normal and reverse). With one side removed, looks good.

When a MOSFET breaks down, it often takes diodes, zener diodes and PWM with it. Check and replace.

-> Just checked now the diodes and the zener diodes -> these are fine.
-> Not sure how to check exactly U9101 which is 3S121 (but I can order this from Ali)

Sometimes they can be tough to figure out, I'm seeing these powerboards for about 20 dollars on ebay etc. At that price what I would do is get a replacement, you want to match up the numbers on the white sticker on the powerboard.

-> I think I will order a replacement too but I want to repair this psu too if possible