LG Flatron 47" Turns on for 10-15 seconds then screen goes black

[sprtcrazy17]

First post here. So I found this 47" monitor with the intention to fix it. The screen turns on, then after a few moments it'll have lines appear in the screen and then go out. Once it goes out, not even the menu screen will appear. So that rules out the external device malfunctioning or the cable (xbox/hdmi).

I've examined all the boards for blown caps, didn't see any(or anything blown).
I'm leaning towards it being bad inverter board(s) after reading the symptons. I just don't want to buy $80 worth of boards without somehow testing them to be sure that's the problem. So that's my mian question, how would i go about testing these specific boards? I couldn't find a wiring diagram online about them to know the pin outs and specs

The picture I first got, looked clean and crisp.


Model number


Power board


T? board


that one board...


Master inverter


Slave inverter




Thanks for the help,


Joe

[sprtcrazy17]

Re: LG Flatron 47" Turns on for 10-15 seconds then screen goes black

**Edit**
Sorry for not using the proper picture etiquette.
Took a vid of the monitor turning on, ignore the background chit chat w/ my drunk roomate.
http://www.youtube.com/watch?v=qNrGg...e_gdata_player

Here's a short clip in the dark showing the backlights being on
http://www.youtube.com/watch?v=7eFUG...e_gdata_player

That's all it'll do, turn on, backlight turns on, but the menu won't display or anything.


Would this most likely be the T-con board at fault?
Does that rule out the power/inverter boards?

I tested the small fuse on the t-con board and it was good, as are all others.


Thanks for any help,


Joe

[Dax Corrin]

Re: LG Flatron 47" Turns on for 10-15 seconds then screen goes black

Hello, welcome. First, caps do not need to be swollen to be bad.
I just recently fixed a couple of Hanns-G 28" monitors that both had bad caps on the power supplies that looked great upon visual inspection. Check the 5V outputs of the power supply once the image goes out to see if there is a problem there. Since the backlights do not go out, I would go to the video/controller board first. One of the 2 monitors I had had about the same issue you do, the image was there for about 10 seconds, then went dark. The capcitors on the video board right next to the voltage regulators were defective. It could also be the TCON board, but start with the one you labeled as "that one board".

[Th3_uN1Qu3]

Re: LG Flatron 47" Turns on for 10-15 seconds then screen goes black

Backlight stays on, that means you can absolutely rule out the lamps and the inverter. Fading with lines pretty much screams Tcon board.

[sprtcrazy17]

Re: LG Flatron 47" Turns on for 10-15 seconds then screen goes black

I tested the video board to see if it had power, that was good. Decided to turn it on, and it was working while the monitor was leaned forward. Moving it made the picture cut out, started jiggling cables and the port on the T-con board is janky. But I got it to work and keep a stable clear picture for the time being. Otherwise a new board will be in my near future I suppose.
Thanks for the suggestions

[budm]

Re: LG Flatron 47" Turns on for 10-15 seconds then screen goes black

You may want to reseating the cables at the T-CON board a couple times.