LG Monitor won't turn on - LG 34UM95 / 31MU97 FIX 

Just AMAZING!!! I just fixed my 10 years old 34UM95-P with the first method (Black on P900 and Red on CS# and SCLK couple of times) and BING!! Thank you Million!!! 🤩

Thanks a lot. The instructions worked perfectly for my LG31MU97. The ship was located on the back side of the board.

This worked perfectly for me! I really appreciate the video, as it is much easier to follow than the written blog post, even for someone with no experience in electronics. Thank you very much!

Thanks a lot. The instructions in the video worked perfectly.

For nearly two years, my LG UM95-P sat unused, and online all I could find was information suggesting that in such cases, it's best to replace the mainboard. Until today, when I finally stumbled upon your video, and now I can enjoy my monitor again. The first method worked for me. Thank you so much for sharing your knowledge.

Hi. Another one here (Spain) who just fixed one of them. It's from a friend. Thanks a million.

Thanks for sharing this info Tom! This brought my LG 34UM95C back from the brink after an extremely nasty series of power fluctuations from a failing UPS. The 3rd option is what kicked it back to life. I immediately performed a factory reset, tested repeatedly, put the back cover on and then mounted it back on the desk arm. Working GREAT! 👍👍

Perfect! I was looking for a comprehensive tutorial for ages. Thank you 👍

Thank you so much! It worked on my LG 34UC87M-B! My board has completely different layout and I actually found IC205 EEPROM on the other side of the board. One of the methods #2 worked (can't tell which, I tried both). Initially after a couple of tries it started once, but then it wouldn't turn on again. I tried a couple of times over two hours, but it wouldn't work. I was just about to give up and order a new empty chip and a programmer (I found dumps on some forums), but I though to give it another try. Not only this worked, but this time the monitor turned on with white screen showing service information (serial number, board etc.) it wasn't there when it started the first time. Did a factory reset, turned it off unplugged it from a power supply, turned it on again after a while. I've repeated it a couple of times. It started each time. I was confident enough to assemble it together. It's works great since then and looks permanent (I hope so). That said I may order a new chip just in case. It's dirt cheap. I just need to polish my SMD soldering skills.

It works for me. - Multimeter setting: 60kOhm(mine doesn't have 20kOhm). - Using #2 and #3. It will turn on after few times. However, unplugging when it's on will make it happen again.

The third option lit up my monitor. Thanks so much Tom. Appreciated for sharing the knowledge. A lot easier than other options like flashing the EEPROM.

Outstanding find! LG 34UC97 working. The first attempt, we flipped the power switch and recreated the problem. Subsequently resorted to only powering off safely through the menu. Might have to replace the IC205. Thank you!

Dude, thank you so much. This brought my monitor back to life and I’m so thankful.

Finally it worked for me with p900 and clk. But I had to put the positive (red) of the amperemeter to p900 and the negative (black) side to clk, not like you’ve shown in the video

Amazing tutorial. My board was different so thank you for sharing so many different methods. On the 31MU97Z - B you can’t really do method 1, so I opted for 2 and 3. I also realised that I was looking at the chip upside down. You need to look for the dot in the corner to find CS. Also listen to the sound of the chip. If it’s pulsing it isn’t fixed if it the tone becomes steady you should be good. Method 2 worked for me I believe (the 2nd one shown) as the third is also labelled 2 in the video. Thanks for helping me fix this monitor!

Great Video Tom, thank you very much!! Do more of this stuff. You saved me today ;) My 34UM95 is alive again.

Lifesaver. This worked for me! Thank you

Thanks You very much for this guide . I save lot of money with repairing my LG 31MU97 ( SCLK & CS method version )

I think you saved my monitor! Thank you!

Amazing! Worked after a few seconds. Most work was getting the rear cover off the thing. Thank you so much! (34UM95-P)

Thank you very much! my monitor works again!

Thankyou good sir, P900 to SCLK did it for me

Thanks for this.

Gracias muy buen video. Nos has salvado. Saludos y un abrazo

3rd option worked great for a lg 34uc97-s. Much appreciated!

Mine worked with 34UC97C-B, Used P700 (pin from switch on the other side of the mb), and CS# - SCLK changing (also other side)

I hope it will work on my LG 34UC87M-B as well. We had a sudden power loss in my neighbourhood and it won't turn on. I wonder what's the difference between UC and UM models, but it supposed to have the same EEPROM chip. I'll check it out tomorrow.

Hi!, thanks for the tutorial!. Unfortunately it doesn't work on my LG. Does the multimeter have to report some particular value on the display to demonstrate that the procedure is working? the value on the multimeter goes from 1 to 0.7 only in procedure 1 only on #cs. in all other procedures the value on the multimeter does not change. Thank you!

I have the same problem after I clean the back of the LG monitor model 27GL650. The motherboard is different from yours. What can I do then? Thanks in advance for helping me.

Hi, I'd like to know what is currently the easiest/best method to use to fix? I have a 31MU97. Took it off a monitor mount and accidentally banged it on my desk as I was taking it off the VESA mount. It wasn't too hard an impact, and only like from 6 inches from desk surface onto desk top. But after that, it wouldn't power on anymore. Tried a different power cable and different outlet with same result. It has been reliable for me for many, many years, until this. I have obtained the firmware .bin file. Wondering if this is the easiest method to try, before multi-meter and eprom chip replacement? If so, what do I need in order to do the firmware update? THANK YOU!

It’s working

Hi, now my monitor is turning on, but just with the backlight. No display, not even menu, no sounds etc. Did anyone had similar situation?

Hi, I have a LG 34UC97 and suddenly wont turning on. I have opened back panel and examine the main board but there is no sign of shock burning and also checked the power adaptor and power chips on the board (with multi meter) and they are all fine. I think I could have the same problem but my main board shape is diffrent and I dont know which one is the chip you are working on it. can you please help me with it?

My 34UM95 doesnt have a rocker power switch and is powered on by the bottom facing button... Is there any way I can manage these fixes with this variation? Trying to hold that button down with my toe while I do it but being a toggle instead of a rocker I dont think it works the same.. 😢

Thanks a lot! It works! But I have the problem that when I turn off the monitor it doesn't work again. any recommendations? I have tried "reset" in the normal menu of the monitor.

Hello, the first method is working to turn the monitor on again, but after about 1 or 2 seconds it turns off before i am able to lift it up to do the factory reset in the menu. Any idea about this? Any advise would be great.

I have the same issue with my LG 34UC97-S but i can't find the IC205 chip. Is there another one built in ?

Hi Tom! I have now been sitting for approx 2 hours with no results. I have some values everywhere but nothing is happening. Any recommendations?

If you’re having issues with fixing, and live in the EU or UK, I am offering the service! Just send me the monitor and I will fix it for a small fee. Thanks

Nice. Sux if it happens again though haha

Here is the thread I based the video on! You can derive a lot of value from the comments under the blog and in there somewhere, there is a comment teaching you how to update the chip's logic so this problem will never occur again. integer13.wordpress.com/2018/04/06/lg-31mu97-not-powering-on-how-to-repair-this-piece-of-sht/

My monitor is gone lmao