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

[Mr_K]

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

In case i have not its a Philips 42PFL4007H/12

[tom66]

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

I cannot find any schematic.
Dodgy Chinese seller has it for £32: http://item.taobao.com/item.htm?id=15108857560 (maybe?)

[Mr_K]

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

Me neither....
This board has different (more) components on it. Like i mentioned at the beginning of this thread.
And i don´t like to order this from china.....

[Mr_K]

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

Did you mean the samsung or the Phillips. I was thinking of the phillips one. Tom and Bud were probably your best bet skimming through checking all the remaining big components
would seem to be all that is left. You tetsted some of the the fusible resistors but did you check them all?

Will check them again. It´s been a long time since i had a look at it. Mostly because i (or the PSU) fried the little IC again and i had to order new ones. Maybe that is a hint?
What do you think about the SMD stuff on the bottom side. Thats a lot! to check....

[selldoor]

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

Yes- that why I said large components. Unless they have changed colour considerably
its a matter of testing every one for short than removing and re-testing - needle in a haystack job.

[Mr_K]

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

Yeah. But i´ll have to fix it since there is absolutely no suitable replacement PSU to find....
Will have a look at it now and report back asap....

[Mr_K]

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

So far i´ve checked every fusible resistors and diodes on the front side. I´ve also tried to power the board with external 5.2V. 5.2V->100R->PS-On With no success. Does this mean the fault is definetly in the 12V/24V section?

[Mr_K]

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

Hey its me again with another approach ;-)
I have finally found some scematics of the PSU. This one is from a benq with different names/numbers on the parts and even some different parts but the cirquit is pretty much the same. Especially in the standby section....
Anyway, this makes me belive that i need to have 5v standby instead of 3v(like its in my case)
HV input is present. There are no 5v between pin 2 and 4 on coil T2.....even with those pins lifted up. Maybe one of you experts can have a look at the scematics and give me a hint where to look?
Wille post more pics if requested.
Thanks in advance

[Mr_K]

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

Ok, i have found the correct schematics!!!!

[tom66]

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

Great!
If you only get 3V instead of 5.2V, places to check are:
- caps C9340, C9341
- inductor L9304 (should be short circuit)
- IC AZ432
- Optocouplers

However, I do notice, there is a Q9301, which when turned on, will reduce the output voltage. This is controlled by a pin, DV5. High on here indicates lower output voltage.

[budm]

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

Do you get the link to work to get the sch? I could not.

[retiredcaps]

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

@budm, attached (as per post #109)

[budm]

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

Thanks retiredcaps, I will study it.
I get this message when I click on the link:
"Oops! Internet Explorer could not connect to www.iernut.bugs3.com"

[tom66]

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

Have you tried using Firefox or Chrome?
I can upload it to tgohome.com. Los Angeles server should be fast for you .

[budm]

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

The SCH shows Q9301, R9339, R9341, R9340 as NC (NOT CONNECTED/NOT USED).
Check ZD9303, OPTO IC9303, REF DIODE IC9304 as Tom suggested.
The more PIN4 (FB) switng toward ground (less voltage), the less output voltage you will get. Check voltage between pin2 and 3 of ref diode IC9304.
When the output voltage tries to go up, the Opto will turn on more to keep the FB pin low.

[Mr_K]

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

Great!
If you only get 3V instead of 5.2V, places to check are:
- caps C9340, C9341
- inductor L9304 (should be short circuit)
- IC AZ432
- Optocouplers

However, I do notice, there is a Q9301, which when turned on, will reduce the output voltage. This is controlled by a pin, DV5. High on here indicates lower output voltage.

The caps and the inductor are fine. We checked IC AZ432 before (Post #93).

Is there a way to check the optocoplers?

[tom66]

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

Just because it's not connected on that model doesn't mean this board doesn't use it...
Opto test requires two meters with diode test. One meter on one side measuring opto diode drop and providing test current. Other device to measure output current.

[budm]

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

He needs to see if those parts are installed on the board or not then to help reduce confusion.

[Mr_K]

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

Just because it's not connected on that model doesn't mean this board doesn't use it...
.

They are not populated......

[retiredcaps]

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

"Oops! Internet Explorer could not connect to www.iernut.bugs3.com"

Though I rarely use IE 8 now, it works fine for me.

I used Opera 12.15 to download and re-upload pdf.