[SOLVED] Monitor main board died - LG Ultrawide 29UM68

OVG

Distinguished
Apr 2, 2013
16
0
18,510
0
So my monitor decided to die :eek:
It is an LG Ultrawide 29UM68.

How it Happened (if it helps...)
For a few days I noticed a light ticking sound at a very steady interval (just loud enough to be annoying) but I just assumed it was a speaker fault and didn't pay much more attention to it. The ticking would go away if I unplugged the USB-C to HDMI cable from my Mac/monitor but resume if I plugged it back into either any port (both on the monitor or Mac if I remember).
I was working away today and then I heard something blow and the monitor shut off. Nothing else on the same power strip had any issue so I don't think it was external. The only signs of life in it is a flickering power light which struggles to stay on (and a weird quiet flicking sound).

The monitor is about 5 years old now but I would say it has only done about 2 years total of 9-5 work which isn't a whole lot.

Can I fix it?
So after phoning a few places that don't repair monitors and others that wouldn't quote me unless I brought it in (which I cannot travel to because of pandemic restrictions) I decided to take off the back cover and have a look :). I can see two places on the board (A and B) which have clearly blown or burned.


The burn at A is likely the original issue (and I wonder if it is linked to the HDMI input in any way given its position on the board).
The blow at B was probably added (or at least made visible) by me when I decided to unplug everything (display ribbons, backlight and speakers) and power it on to see if I could isolate the issue in one of the other components. I unplugged the power adapter from the mains (so I could safely plug it back it from a distance) and didn't wait very long before plugging it into the monitor at which point I saw it spark and burn at B. I'm guessing that wasn't a good idea right? (this is what happens when software engineers play with hardware)
Is this sort of damage to a board normally repairable?

I would rather not dump a perfectly good and nice panel (whether I use it as a monitor again or make some type of smart mirror or some other project out of it :geek:). I may as well learn something now that I have it opened.
I found a replacement board for 50 euro and given that I will likely be charged that in just labor alone if I bring it somewhere it would probably be just best to replace the board itself. Anything above that cost I think I would just replace it.

Given the information above, is it worth perusing a board replacement? How likely is the panel and other components to still be working? Is there anything else I should check so that I don't instantly destroy the next board? I haven't disassembled anything else to see under the board or look at the other ones; should I?

Additional Question
What was the most likely cause of this? Was it most likely just an internal fault (maybe humidity or dust)? Could it be the power adapter? Could it be my USB-C to HDMI cable or my Mac? I just want to make sure that if I repair it or replace it that the same thing won't happen again straight away (or that my Mac won't kill another monitor).
 

jay32267

Illustrious
The "burn" or whatever it is at A....looks very strange.
I've never seen anything like it.

Regardless...I think...most likely....if you replace the board....that should fix it....but there are no guarantees. If it were me...I wouldn't care for that risk.

As far as what else to check....I don't think there's anything else you can easily/readily check before putting in a new board.
 

jay32267

Illustrious
The "burn" or whatever it is at A....looks very strange.
I've never seen anything like it.

Regardless...I think...most likely....if you replace the board....that should fix it....but there are no guarantees. If it were me...I wouldn't care for that risk.

As far as what else to check....I don't think there's anything else you can easily/readily check before putting in a new board.
 

OVG

Distinguished
Apr 2, 2013
16
0
18,510
0
So you wouldn't be too worries about the power adapter?

I just noticed the "burn" at A scratches off pretty clean... maybe a small insect or something got fried?

Would it be safe to plug everything back in and try? or does the blow at B mean there is no point (or can cause more damage)?
 
Last edited:

jay32267

Illustrious
Well....I'm not really sure what happened here>>>

" I decided to unplug everything (display ribbons, backlight and speakers) and power it on to see if I could isolate the issue in one of the other components. I unplugged the power adapter from the mains (so I could safely plug it back it from a distance) and didn't wait very long before plugging it into the monitor at which point I saw it spark and burn at B. "

But if you have a multimeter...you can check the adapter voltage to make sure it is correct before you use it.

If it is correct...you won't fry anything.
 

OVG

Distinguished
Apr 2, 2013
16
0
18,510
0
Right, thank you very much for your help. I will get a multimeter to check with first.

Does damage normally happen after doing what I did? (pluggining out all the wires from the mainboard and then connecting the power) I'm wondering if I actually broke it properly (beyond the burn I scratched off which was shorting it) or if there was a fault anyway.
 

jay32267

Illustrious
"Does damage normally happen after doing what I did? "

This is what had me a little puzzled....because I would answer...no.

I don't think anything should have fried by doing what you did.

I still really don't understand the black dot "A". It is really STRANGE.
 

OVG

Distinguished
Apr 2, 2013
16
0
18,510
0
Yeah mark A scratched off without any visible damage.

I just got a multimeter to test the power adapter and there was no issue there. I'll order the board replacement and give it a go.
 

ASK THE COMMUNITY

TRENDING THREADS