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Looking for advice on cap replacement or board schematic for an LG 24GN600

Doodetz

Jun 3, 2023
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Device: Lg Ultragear 24GN600 Gaming monitor

I have this Ultragear monitor which recently stopped displaying the image, backlight still worked. A new panel costs half the monitor, so I tried fixing it myself. After some investigation I found the broken component, it was a capacitor on led panel board. It got so hot I burned my finger, so I just unsoldered it. Now the monitor works, however, I don't want to leave the spot for the capacitor empty, Looks like there were 3 capacitors in parallel, now there are 2. I have no clue what their function or value is.

Panel serial number is MV238FHM-NG1

I am attaching 2 pictures of the board with the removed capacitor.

Gn6PEvQUm42isp51.jpg

OLjmh1XIjcHBYSOa.jpg
 

Delta Prime

Jul 29, 2020
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Last edited:

kellys_eye

Jun 25, 2010
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Those are called MLCC capacitors and do have a 'reputation' for failing 'short-circuit'. In many situations those types of capacitor are used as supply decoupling devices (remove transients from supply lines) hence the reason the circuit works with it out of circuit BUT you are right to consider replacing it as it actually DOES do something!

As to it's value? Pure guesswork but common values are 10nF and 100nF - I'd suspect the higher value but if you had a test meter that could read capacitance you could compare to the one adjacent to it as it would likely be of the same value.
 

Doodetz

Jun 3, 2023
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@Delta Prime
I would desolder D2 it looks damaged could have got nicked with a soldering iron but just in case
I don't think I will, it's just a small dent and it still works.

@kellys_eye
but if you had a test meter that could read capacitance
I do, but it reads nonsense values because there is some stuff connected in parallel. I can try desoldering a second one and measuring it then, but I may just break it because I don't have any small enough tips for my soldering iron to unsolder smd components, thus, unsoldered capacitor spot looks a little messy.

What's the worst that could happen if I just leave it?
 

Delta Prime

Jul 29, 2020
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What's the worst that could happen if I just leave it?
The domino effect!
You will have a limited amount of time to purchase or require the proper equipment if you wish to fix it.
As previously stated they are decoupling capacitors another event such as transients on the power lines will destroy the power supply as it stands the circuit itself is stressed, failure is imminent. Good luck to you
 

kellys_eye

Jun 25, 2010
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as transients on the power lines will destroy the power supply
Not really - the transients may well affect other parts of the circuitry causing weird faults in a digital sense but it's not going to harm the PSU.

I can try desoldering a second one and measuring it then, but I may just break it because I don't have any small enough tips for my soldering iron to unsolder smd components,
You'll be surprised how much heat those SMD devices can withstand. There are YT video tutorials on removing components and a capacitor like that is 'childs play' (when you know how). You won't do any harm by putting another capacitor of 10nF or 100nF right where the missing one is - having one of 'any' value is better than not having one at all. If you have any junk circuit boards (or can get hold of one) then such capacitors are 'all over the place' so you'll get practised at removing them before attempting to resolder them!
 

Doodetz

Jun 3, 2023
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Not really - the transients may well affect other parts of the circuitry causing weird faults in a digital sense but it's not going to harm the PSU.
That's good news

If you have any junk circuit boards (or can get hold of one) then such capacitors are 'all over the place'
Yes I do and even can somewhat carefully unsolder from them.
The problem is that that the lcd board is really thin and its ground is connected to the backplate of the lcd panel, so heating it essentially heats up the panel itself, so soldering on it is hard. I can't take it off because of the data connectors to the panel, they are permanent and really fragile.
I just left it as is being afraid to damage the panel and will just use the display not at its maximum brightness/hertz settings. I'll see how it goes.

Thanks for the help
 

Delta Prime

Jul 29, 2020
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Not really - the transients may well affect other parts of the circuitry causing weird faults in a digital sense but it's not going to harm the PSU
LG 24GN600 a relatively inexpensive affordable and purchased by my way too many nieces and nephews because I repair all of their electronics if possible my comments were made out of experience.
But I am compelled to recognize your sound and well-educated advice theoretically.
 
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