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Can I fix a missing capacitor by just soldering the spot short? (lemmy.blahaj.zone)

submitted 7 months ago by [email protected] to c/[email protected]

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So, I've got a laptop screen that's giving up on me. 2/3 of the screen runs alright but the 1/3 on the left edge is acting weird. Half of the broken section displays an image but the image smudged and weird, while the other half is just dead. I opened it up to see what's up and, lo and behold, a wee tiny capacitor is missing (I know it's a capacitor 'cause I looked of the board marking, C248).

Now I'm wondering, since ordering a single capacitor just for fixing this screen is not worth the effort, can I just... put some solder in there to at least get power to where it needs to go? I know it's definitely not ideal but, this is an ancient laptop. Putting in the effort to fix it perfectly is not exactly a great value proposition. What I want to know most is, will the screen be damaged if I do this, or what could go wrong if I do this?

I'm pretty new to DIY electronics fixing so sorry if this is a stupid question. Thanks in advance y'all. Cheers!

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[–] [email protected] 19 points 7 months ago* (last edited 7 months ago) (5 children)

The purpose of a capacitor is to build up charge slowly, and release a larger charge suddenly, under very specific conditions. The specific conditions are determined by the exact model of capacitor.

A direct connection at a point where a capacitor once was won't do the job. It'll both provide too much power (compared to zero) and too little (compared to the burst of extra power on release).

Shorting a spot where a capacitor once was will almost certainly damage other components.

If you're sure there was a capacitor there, and can find out which one, then you want to install (solder in) a fresh capacitor of the exact same make and model.

[–] SmoothIsFast 10 points 7 months ago (4 children)

Shorting where a capacitor was won't provide any power, it will most likely cause a short circuit, potentially resulting in sparks and flames.

[–] [email protected] 0 points 7 months ago (1 children)

It can let the magic smoke out, yes.

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