LG 55SM8100AUA, no display, audio and other features working fine.


Novice Member
I recently got my hands on a 4k LG nanocell from my friend, he bought the TV for his parents about a year or so ago. It worked fine for them initially, it was dropped when it was delivered and has a dented back panel, but there were never any issues when in use. About a year into use it apparently stopped displaying anything, so they decided to get rid of it, and it ended up in my hands. Been trying to give a shot to fixing the thing since the panel itself looks fine.

Audio works completely fine and I can tell that the TV is still working. When the TV is first booted up it often times displays a picture for a second or two, and then the image freaks out and corrupts into vertical lines. It either goes black after this or cycles back and forth between normal and glitchy for a few seconds. When the display goes out the backlight remains on, no dark spots that I have observed, so I don't think it's a backlight issue.

I've read through service manual and replaced both the main board and power board with new boards from ebay, after replacing the power board it seems to last a second or two longer than before, but the issue still remains. Curious if anyone has any ideas of things to try, when the display works it looks absolutely pristine, no marks or issues that I can see, so I have a hard time believing the panel is simply dead. Thanks for any help!

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