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I'm asking this because when I was replacing my laptop battery, I accidentally hit and broke/disconected one SMD capacitor off the board, then I turned my laptop on, it made some weird electrical noises while booting and apparently is working fine without the capacitor.

I'm worried because I'm overseas in the UK and I'm don't know how much they gonna charge me.

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  • \$\begingroup\$ Different capacitors/resistors do different things, so it's hard to know without a schematic, board layout, and designator. If the electrical noises persist, though, or you see other anomalous behaviour, I'd quit using it for safety reasons. \$\endgroup\$
    – Cristobol Polychronopolis
    Commented Jan 31, 2020 at 21:36
  • \$\begingroup\$ Did you remove it completely or is it still there but cracked? \$\endgroup\$
    – pipe
    Commented Jan 31, 2020 at 21:50
  • \$\begingroup\$ It's still there but only one part disconnected \$\endgroup\$
    – Jeff QW
    Commented Jan 31, 2020 at 23:01
  • \$\begingroup\$ It is quite possible that you did other damage. \$\endgroup\$
    – copper.hat
    Commented Feb 1, 2020 at 14:46
  • \$\begingroup\$ You can always go to a computer shop and ask how much it will cost. There’ll be multiple in each town, try a few different ones until there’s one you think seems reputable and is a good price. \$\endgroup\$
    – Tim
    Commented Feb 1, 2020 at 20:28

1 Answer 1

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You've just rediscovered Muntzing.

Quite often you can remove some specific component on a circuit board and the device will keep functioning - but not as well, capacitors being the primary target.

A lot of components are absolutely crucial, but some are there to make the device "better". The capacitor you dislodged was likely mounted in parallel with other capacitors to increase the capacitance near a specific part. The remaining capacitors will "take up the slack" but it might be that you will see one of these effects…

  • Computer will restart when it's unusually hot or cold
  • It will not last as long
  • Random bit-flips in RAM
  • It will radiate energy and disturb sensitive devices like your Wi-Fi
  • And more!

You have already discovered one effect. It appears that under load, you can now hear audible noise. This could very well be because other capacitors have to pass more current, and because they are microphonic (which works in reverse too), they can emit sound.

If I were in your situation I would make sure that the data is safely backed up (because any bit-flips may alter data if written out to storage), and then keep using it.

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    \$\begingroup\$ +1 if only for Muntzing. I'm that shallow. :-) \$\endgroup\$
    – a concerned citizen
    Commented Feb 1, 2020 at 17:00

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