50" LG Plasma TV issues

[vortalexfan]

Originally Posted by dr.ido

I don't know that exact model, but the following applies to a lot of LG plasma TVs -

Disconnect the main board (the one with the HDMI /etc inputs on it) from the power supply.

Connect power - without the main board connected it will power up. If you get the grey screen and it now stays on then the power supply and sustain boards are probably ok.

Find the AUTO_GEN pins on the controller board - short these pins and the controller board will generate test patterns. This will confirm that you panel, sustain boards and power supply are good.


Most of the time the main board is the problem. Often you can reflow the main IC on the mainboard with a heat gun and this will fix the problem.

Thanks for the tips. I found the auto_gen pins you were talking about, mine unfortunately had no pins present and it was marked ext_auto_gen on mine so it seems mine wasn't meant to automatically generate test signals. But I'll still try what you said though about testing the tv without the mainboard connected and see how it works. How would I reflow the solder around the main chip on the mainboard with a heat gun? The main chip looks like it might be surface mounted and has a large heatsink over it that's covering the solder connections for the main chip to the mainboard.

[vortalexfan]

OK So I replaced the capacitor that I had read elsewhere that was supposedly the problem and it still is acting up, so I tried powering on the TV without the main board hooked up to the TV like you suggested and it wouldn't even power on or even attempt to power on without the mainboard hooked up.

Here's a picture of the TV's mainboard posted below. Is the big black square heatsink in the middle of the mainboard the main chip you were talking about? If so then I don't see how I could reflow the solder on that chip because of it being surface mounted plus the heatsink would probably destroy the chip if I hit it with a blast from the heatgun.