LG flatron W2243S 2 sec power of without picture

[mshone]

Hi, i am newbie on this forum and i apologise for my mistakes in gramar, but i hope that all will understand me.
For hoby purposes, i try to fix one LG flatron W2243S.
Symptoms:
-When i press pwr button, red LED after 2 sec going in off, without any reasons.In the meed-time, on the display nothing shows /even a little light/. Also, in this 2 sec-period, i can hear very quiet buzz form pwr-inverter board.

I tried next:
-test CFL, all 4 are OK, i can see the light on display
-i made visual inspect pwr-inverter board, main board and on both sides and didn't see nothing suspicious /soldering, junctions, capacitors etc/
-i inspected fuse, and it is ok.

I am trying to find service manual for this model of pwr-board /715G3447-1/ to see schematics, but i have trouble with this.

Please some instructions for further steps.Tnx.

[selldoor]

Re: LG flatron W2243S 2 sec power of without picture

Post good clear picture of both boards.
How did you test the ccfls

[addytzu123]

Re: LG flatron W2243S 2 sec power of without picture

Hi,
Check if the attached manual matches your monitor!
Verify and post the voltages produced by PS.

[mshone]

Re: LG flatron W2243S 2 sec power of without picture

sorry for my absence from here.Have some jobs to do in family.Took pictures, during day i will post here.Also, for service manual thing that is appropriate.I will do detail check. Tnx addytzy. For selldor, i tested CCFLS with DIY kit from this tutorial
http://www.youtube.com/watch?v=vhEGW46uCVc

[selldoor]

Re: LG flatron W2243S 2 sec power of without picture

Ok so does this "i can see the light on display" mean you can see a very dark image when the backlight is off?

[mshone]

Re: LG flatron W2243S 2 sec power of without picture

actually not see the image, i cant see only light, dark-but light, this /if i am not wrong/ meens that CCFL-s are ok ?

[selldoor]

Re: LG flatron W2243S 2 sec power of without picture

Think we are struggling with translations but you said you tested the ccfls and they were good. Can you post clear pictures of the front and back of the power supply?

[mshone]

Re: LG flatron W2243S 2 sec power of without picture

Yes, my english skills are on "Tarzan level".

[addytzu123]

Re: LG flatron W2243S 2 sec power of without picture

There is a fuse F902 near the output connector of the PS, did you check it ?
What voltages you have on the pins of the connector?

[mshone]

Re: LG flatron W2243S 2 sec power of without picture

I use mutimeter.
i was found 3 fuses,F901, 902 and F802-all 3 are ok. but, diode D904 near MOSFET has BEEP on diode test in both ways. And MOSFET is suspicouus. Capacitors looks good,
other diodes top of board are ok, shotky is ok....No trace of higher temperature...

I am not sure how to test voltages.Should i reconnect all again, to test voltages?

[mshone]

Re: LG flatron W2243S 2 sec power of without picture

hmmm, i was test Q902, and all 3 ways has contact. Also, on the other side of board, R903,904,905,906,908,910,938... has OL on lowest settins of ohmmeter. Seems like all board are burned, but it is strange that all fuses are ok...