Faulty Philips PSU (715g5246-p01-000-002s )

[Mr_K]

Re: Faulty Philips PSU (715g5246-p01-000-002s )

Hi - what is this- may be just a link or the picture, but it looks a bit odd.

You have excellent eyes! I suspected this one, too. It looks odd because i lifted two pins for testing. From this view, the top left one and the lower one. Problem still remains....

[Mr_K]

Re: Faulty Philips PSU (715g5246-p01-000-002s )

So, i made a cut in the 12V line. Pls see the picture for details

Edit: Picture updated with another cut. Blue lines are jumpers on the top. No short below this cut

[tom66]

Re: Faulty Philips PSU (715g5246-p01-000-002s )

OK, the other possibility is a failed MLCC (ceramic capacitor.) There is a small brown capacitor across the +12V and GND, right near the connector. Remove this and check if the short persists. It is only for EMI so not crucial for operation. Replacement should be with a 1uF 16V or 25V, 0603 device.

[selldoor]

Re: Faulty Philips PSU (715g5246-p01-000-002s )

Well - not a lot to check? Make sure the solder joints are not touching at the connector
12v and gnd are pretty close. Then chack those little smd components that go from 12vtrace to gnd trace.

Edit
Just beaten to it!

[Mr_K]

Re: Faulty Philips PSU (715g5246-p01-000-002s )

No, that didn´t do the trick

[tom66]

Re: Faulty Philips PSU (715g5246-p01-000-002s )

So, let me understand this. DMM in ohms across 12V and GND. Reads dead short?

[Mr_K]

Re: Faulty Philips PSU (715g5246-p01-000-002s )

Reads 0,5kOhms With cuts still open

[tom66]

Re: Faulty Philips PSU (715g5246-p01-000-002s )

And across the transformer tap it shows a short?

I fail to see the problem here -- this is quite normal. A transformer winding is a piece of wire inductively wound around a core. Ideally, it has zero resistance.

[Mr_K]

Re: Faulty Philips PSU (715g5246-p01-000-002s )

I can´t mesure ohms between the transformer pins and ground. It alters very fast and i´m only using a multimeter.

[tom66]

Re: Faulty Philips PSU (715g5246-p01-000-002s )

It should be steady -- TV/PSU must be unplugged.

[Mr_K]

Re: Faulty Philips PSU (715g5246-p01-000-002s )

It should be steady -- TV/PSU must be unplugged.

Sure!!!

[selldoor]

Re: Faulty Philips PSU (715g5246-p01-000-002s )

Can you unsolder the long link - will shorten the problem zone.

Did you test the resistors crossing the line? and is there a cap or something
pinkish lines - what is the odd cherry coloured joint

[budm]

Re: Faulty Philips PSU (715g5246-p01-000-002s )

Can I see the label on the white connector with a bunch Voltage labels next to it, I cannot read them on the picture.
I expect the 5V stanby to be working sinc the 12v is switched on by the main board.
Philips model number and chassis number? I also see MLCC right across the 12v output close to those two bleeder resistors.

[tom66]

Re: Faulty Philips PSU (715g5246-p01-000-002s )

We already ruled out the MLCC. After the diode it was my prime suspect. But I really am not sure where the short is any more.

[Mr_K]

Re: Faulty Philips PSU (715g5246-p01-000-002s )

Can you unsolder the long link - will shorten the problem zone.

The blue one? It´s unsoldered. See post #22

Did you test the resistors crossing the line?

They seem to be fine. They would have much more ohms and not shorting out when failing.

Pls see the pic for details.....

[Mr_K]

Re: Faulty Philips PSU (715g5246-p01-000-002s )

Can I see the label on the white connector with a bunch Voltage labels next to it, I cannot read them on the picture.
I expect the 5V stanby to be working sinc the 12v is switched on by the main board.
Philips model number and chassis number? I also see MLCC right across the 12v output close to those two bleeder resistors.

Which label exactly?

The TV is a 42PFL4007H/12. I didn´t find the chassis number and i´ll have to wair for tomorrow to look it up....

[selldoor]

Re: Faulty Philips PSU (715g5246-p01-000-002s )

He means the values shown in the box underneath _ I tried to enlarge and improve but could not
On/Off
DIM
+12v
+12v
Gnd
Gnd
Gnd
24v
24v
PS-on
5.2v
5.2v

[selldoor]

Re: Faulty Philips PSU (715g5246-p01-000-002s )

Its nothing daft like the link on the top of the board pressed down onto the socket pin ends

[budm]

Re: Faulty Philips PSU (715g5246-p01-000-002s )

Reads 0,5kOhms With cuts still open

So it shows 500 Ohms (0.5K Ohms), that is not dead short, that sounds like the reading of those 3 resistors in parallel with the 12V output. I think we need to get the 5vstby working first.

[selldoor]

Re: Faulty Philips PSU (715g5246-p01-000-002s )

Good eyes - perhaps- but totally missed that there was no 5v.
Mr K are there any voltages on the connector