I was trying to unscrew a really stubborn screw in a computer and in the process some of the screw’s head got scraped off in little tiny flakes. I then assembled the laptop back together without having blown or removed those little metal flakes. Might they get onto the motherboard or something and cause a short circuit?
They might, rabbit, they might. Metal flakes a tightly pack circuitry isn’t an ideal situation.
Anything socketed would be suspect. The flakes could make their way and bridge two or more pins.
But, the way laptops are built today there isn’t much sockets aside from major assemblies and cables.
There’s still plenty of exposed solder pads, pins, and traces on the PCB. All of those could be subject to shorting out from metal filings.
If you disassembled & reassembled it once, it should be easy enough to do it again, so that you can blow or vacuum it out. And that’s worth doing, even if it’s only a slight risk of a short circuit.
If you vacuum, remember that this can create extensive static – keep the machine & yourself grounded!
OK thanks, but might the blowing of compressed air simply push the metal shavings around so that it actually makes short circuit likelier?
Remove the battery first.
I was working on some equipment at a steel wool factory. The power was hard wired and I couldn’t turn off the breaker since that would shut down an active production line. Sure as shit, the second I got the housing opened, some wool (which the entire place was covered in) fell onto the mainboard and the thing died. The fuse was blown but I couldn’t be certain if other componets had also failed until power was restored. I had to find a Radio Shack and buy some fuses and a holder. Then, I had to cobble those parts together since the original fuse was a little radial one and the new fuse holder was axial. Fortunately, it fired back up and was working again.
Same thing will happen if you wiggle the computer around. At least you can turn the thing off and dislodge the ones that will dislodge easily.
I’ve “built” many computers (gaming rigs and modified laptops) when I was a teen (when it was affordable, before it was cool 
) and have left metal shavings behind from modifying the cases (putting massive cards in microATX cases) as well as from the cheap chinese screws that flake even when you use the correct screwdriver (had some cases with Torx :smack:), leaving Mobo spacers in the wrong spots, even modifying the ram in laptops with makeshift heatsinks and the like. Never had an issue and perhaps most importantly, I would give them a tap and shake, use compressed air and forget about it.
Never had one fail.
The PCB traces will be protected by the solder-resist, a clear insulating layer. You won’t see the pads because with surface-mount technology the pads are mostly or wholly under the components.
The vulnerable spots will be the legs on the ICs.
Unless there’s a conformal coating on the PCB - which is doubtful - all adjacent pairs of solder junctions and component terminals will be vulnerable to shorting.
I would open the case and blow it out. If you can, invert the PCB and blow in the vertical (“up”) direction so that gravity pulls the debris down and away.