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

submitted 5 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] 2 points 5 months ago (1 children)

will the screen be damaged if I do this

Yes. Probably immediately and violently if the capacitor was used as a low-pass filter or a similar configuration. If the capacitor was used in a high-pass filter (or similar), then the damage might take some time to appear (if at all), and it might not be as violent.

what could go wrong

If it was a low-pass filter or similar, then expect other components to overheat quickly. Depending on what type of component dies first, you might be lucky and just get a light-emitting resistor. If however an electrolytic capacitor dies first, then you'll probably have to deal with a lot of nasty smelling smoke, that might take days to get rid of. Also, overheating electrolytic capacitors can explode if you are unlucky enough, what might do physical damage to the circuit board, or even the casing or panel.

[–] [email protected] 1 points 5 months ago

Thanks for the clear and concise answer, my man. Cheers!