LG Monitor mainboard turning on issues - Page 1
Forum section: electronics / beginners

author: nomorevideos
author_rank: Newbie
timestamp: August 29, 2019, 02:24:49 pm
content: I have an LG Flatron IPS234 monitor that I bought way back in late 2013. Around half a year ago it started to act up and upon turning it and my PC on it'd have some trouble getting started. It would basically turn off and then on over and over (while very briefly displaying an image) until it would finally relax and display the image. It'd get worse over time and take longer to finally calm down and eventually it would take 10+ minutes and like 50 attempts or so even on lower brightness. Initially lowering the brightness helped, but afterwards yeah it didn't help anymore. I personally thought this must've been a dying/fauly capacitor and because I can't solder myself I just opted to get a new mainboard. I ordered one from China. It wasn't the exact same model, but besides 1 missing little part on the board everything was the same. Ports all lined up and once I switched it out it worked perfectly fine. A few weeks later I once or twice experienced very brief start-up troubles again, but only for a few seconds and they stopped after those 2 times. Couple weeks after that and they showed up again and ever since then they're present whenever I turn my monitor on in the morning. Right now it'll turn on and off and on and off and even leaving it be for 10 minutes doesn't fix it anymore. So far the only fix is to unplug the HDMI cable and wait for the monitor to display a "please connect a cable" message, then partially plug it in for another message to appear, but only let it appear for a split second before plugging it in fully. This usually doesn't work on the first try but after a few attempts. Still with me? Good. So my question is, what could the issue be? Obviously it's not my GPU since switching the boards out helped right away. It's not the HDMI cable itself either, I tested it with another device. So I am left with either this board going bad or the display itself going bad which once again idk if that's the case since switching boards did instantly help. I checked the old mainboard and there's no leaky capacitors, at least what I can see, and they're not bulging either. The monitor has a DVI looking port (no idea what it's called, it's the same as the DVI looking thingy on my 1060 6GB), but I do not have a cable to check if the monitor's HDMI port is going bad.My question is, what can cause the monitor to have these kinds of issues? Where after being turned off for a few hours it'll have these start-up issues.I always thought of it as a capacitor issue since lowering the brightness would initially help the original board. Lowering the brightness would main there's less "power" excuse me, flowing through the board. Again switching board instantly helped and the new one for those 2-3 weeks had no issues displaying a bright image.If needed I can take some pictures of the old board, but I doubt it'll help.

author: tunk
author_rank: Super Contributor
timestamp: August 29, 2019, 03:55:54 pm
content: Have you looked at the power supply?

author: nomorevideos
author_rank: Newbie
timestamp: August 29, 2019, 04:41:52 pm
content: I have not checked the power brick, but as I said I do not believe it's the power brick or my PC since switching from the original mainboard to the new one from China instantly fixed the issue at that time. I'd like to know what kind of issue on the PCB could cause this behavior.

author: dcbrown73
author_rank: Regular Contributor
timestamp: August 29, 2019, 08:38:19 pm
content: In the future, you might want to break a post like that up into paragraphs. That is difficult to read like that (huge blob of text) to the point that I had to just stopped reading it.Anyhow, good luck on your monitor.

author: nomorevideos
author_rank: Newbie
timestamp: August 30, 2019, 08:49:52 am
content: TL:DRMonitor trouble turning on, flickering on and off, suspect capacitorGet new mainboard from China because I can't solderSwitch out old with new board, instantly solves the issueNew board also goes baddy bad after 4 weeks or soWhat could the issue be? Did I just get unlucky with the replacement? Even if so, what could cause this issue and could I get it fixed by someone who knows how to solder?

author: Psi
author_rank: Super Contributor
timestamp: August 30, 2019, 10:07:46 am
content: Yep, i also suspect bad caps.Could be in the PSU brick or in the monitor itself.PSU is having a hard time starting up because the capacitance left in the caps is pretty low.

author: nomorevideos
author_rank: Newbie
timestamp: August 30, 2019, 09:37:17 pm
content: I will look into getting a replacement then and see if that helps. The only real thing I think is weird how switching out the board originally helped AND how currently I have to plug the HDMI in and out in a specific way in order to make it work. If I wasn't short on cash I would've thrown this monitor out half a year ago and bought a new one tbh.