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

[budm]

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

"ook some time to get my hands on the IC to replace the old one. After replacing, my readings are:
Here are the readings:
On/Off 0V
DIM 0,01V
+12v 0V
+12v
Gnd
Gnd
Gnd
24v 0V
24v
PS-on 3.3V
5.2v 3.3V
5.2v 3.1V"

So now the 5V stby power supply is working after replacing the IC, but are you only 3.3V instead of 5.2V as shown in your chart above?
Your meter is good? It still bother me that with 225VAC for your power and you only get 308V on the main filter cap, it is telling me that the cap is not charging up to the peak of the voltage.
We also have to work on the 12v circuit next, but we must make sure your meter is OK.
Another point also is the reading of the two pins of the 5.2V connectors, the two pin are tied together but some how you are getting 3.3 and 3.1 V reading, they should be the same.

[Mr_K]

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

Hey, thanks for coming back here!
I´ll try to answer your questions:
My B+1 is 318V at the main filter cap.
Regarding Standby Voltages: I made a mistake here: There is a 13Pin connector with only 12 Pins labled. Look at the downside of the board. Below the two 5.2v Standby pins is an additional pin. I mixed them up:
Correct readings:
PS-on 0V
5.2v 3,37V
5.2v 3,37V
"pin13" 3,36V

The main problem left might be the 12v rail. Is it possible that somesthing in the 12v circuit is drawing power from the 5v standby?

[tom66]

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

I do know of some Philips PSUs that change the +5.2V to +3.3V in standby mode to save power, it could be that.

[Mr_K]

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

That would be even better. Tv LED is blinking 3 times. This is related to my 12v problem. So standby power MIGHT be ok.

[budm]

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

Well, I need to trace out the 12v power supply section next and draw up the diagram.

[budm]

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

By the way, did you put all those components you have removed and cut traces back at the right locations, just to be sure.

[budm]

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

Hey, thanks for coming back here!
I´ll try to answer your questions:
My B+1 is 318V at the main filter cap.
Regarding Standby Voltages: I made a mistake here: There is a 13Pin connector with only 12 Pins labled. Look at the downside of the board. Below the two 5.2v Standby pins is an additional pin. I mixed them up:
Correct readings:
PS-on 0V
5.2v 3,37V
5.2v 3,37V
"pin13" 3,36V

The main problem left might be the 12v rail. Is it possible that somesthing in the 12v circuit is drawing power from the 5v standby?

OK, you are not getting PS_ON to turn on the 12v/24v POWER SUPPLY.
TV unplugged, Put the DC voltmeter on the PS_ON pin, plug the TV into the outlet, take the reading, hit the power switch, take the reading, hit the power switch again and take the reading. I need to see if this PS_ON voltage change state at all.

[Mr_K]

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

All components are in place and all cuts are closed.

I´ll check PS_ON status as soon as i get home.
BTW can you explain the difference between PS_ON and ON/OFF pins?

[tom66]

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

ON/OFF is usually for backlight, just routed through PSU (reduces wiring.)

[Mr_K]

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

Thank you.
I´ll not be able to test the PSU inside the TV before tomorrow.
When i bridge standby to ps-on nothing happens to 12v. More test will follow tomorrow.....

[budm]

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

The reason I ask to check the voltage on PS_ON when TV is off and when TV is on is to find out if this Philips TV uses Active High or Active Low logic, some Philips uses >3v for OFF instead of ON.

[Mr_K]

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

PS_ON: When plugged in, its 2.9V. After ~1sec its 3.3V and shorted to standby. Pressing the Power button or CH+ doesn´t affect PS_ON.

[budm]

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

"After ~1sec its 3.3V and shorted to standby" Do you mean the PS_ON was at 2.9 and it then goes up to 3.3v which at that point the TV goes into standby?
The PS_ON should toggle between two voltage values (high and low) when you activate/deactivate the power switch.

[Mr_K]

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

No, PS_ON is at 2.9V as soon as i plug the TV in. After ~1sec it goes up to 3.3V. I have checked with my meter that it has continuity to standby PIN when at 3.3V wich it hasn´t when tv is not plugged in. So anything must have switched and connected PS_ON to STANDBY PIN.
I do NOT measure any changes (no high or low) when pressing the power button.
My guess is: TV tries to power on as soon as plugged in.->PS_ON is switched to 3.3v->With 12v missing, tv goes into some kind of "error mode"->thats why the power button doesn´t affect PS_ON

[Mr_K]

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

Still no luck with this one. Any more help please?

[Mr_K]

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

I found a faulty transistor. (Q8101; The lower one of the two on the top below the sticker......pic will follow....) Its a K2510AK
First question: Can this one be responsilble for 12V not being present.
Second question: Can someone please tell me a suitable replacement part. RS would be nice. Thanks!!

[tom66]

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

To get an orderable part number, add "2S".

2SK2510
http://australia.rs-online.com/web/p...stors/5485125/

^Yeah, in Australia. Seems to be out of stock everywhere else.

[Mr_K]

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

Hmmm...discontinued product. Thats why i´m looking for substitution. And of course it´s faster ;-)

Would a IRL540N fit? I´d like to double check this for safety reason!!

[tom66]

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

60V, 10mOhm fet.

This is 60V, 7mOhm.
Should be fine.
http://uk.rs-online.com/web/p/mosfet...stors/6875324/

[Mr_K]

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

Should´t it be for 100V?