February 26, 2021

LG 34UM68-P wont power on

I love my LG 34UM68-P ultrawide screen monitor. But after removing the power from the back to move it off my desk without powering off the monitor first, I was sad to find my LG 34UM68-P Wont power on. I was so disappointed as it was also out of warranty. I am glad to say it is finally fixed.

The problem: LG 34UM68-P Wont power on.

(This post is for entertainment purposes only, If you do not know what you are doing you should have a professional fix your monitor as you could injure yourself or damage your property. )

Not sure why, but for some reason after removing the power without powering it off from the monitor (I just unplugged it from the back) My LG 34UM68-P Wont power on. The little purple light still glows at the bottom of the monitor, but otherwise it is dead. It was disappointing as I love this monitor and use it everyday for fun and work. I even tried swapping it out with a Samsung 34 inch Ultrawide that had higher resolution, but it just did not look as good to me. I like the IPS panel of the LG over the VA panel of the Samsung.  For the me 2560×1080 resolution of the LG 34UM68-P is perfect. Especially when paired with another 27inch LCD at 1920×1080. For me its a perfect setup for my desk.

Ok, back to the issue.

Since I didn’t like my new replacement monitor I decided to try fixing the LG 34UM68-P. I took the stand off, then removed the back panel. Once I looked inside I figured the problem would be the main board a EAX66876002 (1.0) or the power button board which looks like the number was EAX65469603 (It was hard to read as it was so small). So first I took some closeup pictures and zoomed in and looked for broken solder joints, or issues. I found nothing that looks bad. The capacitors also visibly looked fine.

LG 34UM68-P EAX66876002 main board and power board
Quick inspection inside the LG 34UM68-P

 

Finally after not finding anything I figured I would have to get a new main board and try it out. Looking on the internet I could not find the EAX66876002 for sale. I did find some EAX66876001 for sale but looking at the picture, it was missing one of the connectors I needed. Not sure what that model is for.

Solution

The fix for this wasn’t free.  What I ended up doing was finding a broken LG 34UM68-P on eBay with a cracked screen and buying it for $50 dollars. I swapped out the mainboard first and that fixed the issue. Snapped the back cover back on and I was good to go. The monitor is working perfect again. I do count myself lucky for being able to find a broken monitor to grab a mainboard from. Here is a picture of me about to swap it out.

new EAX66876002 board about to be installed

Side note: I did read somewhere that the LG 29UM68-P board would also work but I can not verify that. I was just informed by someone who saw this that the LG 29UM68-P version of the board is missing half of the power circuit for the LCD backlight, So do not get that version if you have the LG 34UM68-P (Thanks for the heads up! Super appreciated!). But I was keeping an eye out for one of those as well and was going to investigate further if I found one.  Anyways glad my LG 34UM68-P monitor not powering on issue is finally fixed.

For reference here is the link to the LG website for the manual and specs.

If you need some RGB backlighting for the LG monitor or TV you might like this post here.