Thank you [USER="477674"]EazyBone[/USER] and [USER="71977"]nomoresonys[/USER] for your help with this. I got a new main board and the TV is fixed, so it was the main board after all. I suppose the random colors was also a symptom of that, but I can't be sure now, as I don't know what's supposed to be on the screen in such a failure mode.EazyBone...

I'm not sure I follow.... How do I take a single pin out from the connector without damaging it?



I'm not sure what lines are you talking about......

That's what I tried to test when I bridged POWER_ON with DRV_ON. My thought that if there is voltage on DRV_ON then the backlight should come on.



I tried that and it wasn't totally black as when it's off, it looked like there was something, but it wasn't a picture that would make sense - it was like just random colors in different pixels.



I bridged it with the main board connected. Just shorted the two contacts with a wire briefly....

That was my thinking too, but how can I be sure? Can I somehow exclude the possibility that this is the power supply? I tried bridging the POWER_ON to DRV_ON to see if the backlight comes on, but it didn't. I just don't want to buy a new main board without knowing it will fix the issue. Also, If it is the main board, is there a way to troubleshoot why it's not sending the DRV_ON signal?...

Hi,

I'm new to this forum, so this is my first post. I have an LED TV LG Model 60UH8500 that stopped working suddenly. The standby LED is on, but when I try to turn the TV on either using the remote or the power button on the TV, the red standby LED blinks 3 times, but nothing else happens - the TV screen stays dark, no picture and no sound.

Here is what I did so far... I removed the back cover and checked both the power supply board and the main board for any obvious visual cues such as burnt diodes, bulging caps, etc. Nothing observed. I checked 2 fuses - GOOD, tested...

Hello,

I'm a software engineer from NJ and I dabble with electronics to some degree, but I'm not a pro by any stretch. I am able to troubleshoot stuff with some guidance, replace boards, even solder some components onto the board.