Chosen Solution
I have a 55 in LG TV. Similar to other threads related to screen not powering and on red light blinking 3 times. After that the red light disappears for about 10 min and then returns. Any attempt to turn back on yields the same result…light blinks 3 times then goes away. I’m relatively inexperienced when it comes to this type of stuff but willing to mess with things to try a fix. I’ve seen several posts concerning capacitors replacements but also some other posts indicating the issue could be coming from multiple sources. Where would you recommend problem shooting first? Update (06/26/2019) I got the back off. Here are the pics of the two boards. after taking the back off I plugged unit back in. Screen came on but was not responsive. Unplugged and plugged back in. Now red light. I do have a green light flashing on the power board. Update (06/26/2019)
Bob Heath right now it does sound like a power board issue. We would need to see what boards your TV has. I have not seen bad capacitors in a while. Samsung was the bigger offender with bad caps. LG has issues with poor backlight arrays. It will help if you can post some pictures of your boards and layout etc. with your question. Remove the back from your TV and take some good pictures. Post those with your question Adding images to an existing question. check the connector that has the cable from the power board to the main board. All the voltages should be stenciled on your power board. Check the standby voltage first. No standby voltage=bad power supply. Let us know what you get.
Replaced the main board. Working good as new now.
