While moving an M.2 SSD from my PS5 into my PowerSpec PC, I accidentally dropped the tiny mounting screw into the case. It landed near the opening above the power supply at the bottom, and I briefly heard it rattling when I gently tilted the computer. After removing the side panels and searching carefully with a headlamp, I still couldn't see it and was worried it might have fallen into the power supply. I eventually found it trapped in a ridge at the bottom of the motherboard backplate before needing to remove the motherboard. What's the safest way to handle a loose screw inside a PC, and how can I avoid this happening again?
3 Answers
Don’t turn the computer on while the screw is unaccounted for. Inspect every corner, gap, and ridge in the case, and consider removing the power supply so you can check around it safely. Avoid aggressively shaking the PSU itself; if the screw got inside, opening or replacing the unit is safer than trying to force it out.
A magnetic pickup tool is really useful for situations like this. A magnetic screwdriver can work too, and if yours isn’t magnetic, you can hold a strong magnet against the shaft to pick up the screw. Before powering the PC on, make sure the screw is definitely out and check around the case carefully.
This is practically a PC-building rite of passage. Tiny screws love getting stuck in the strangest places, so it’s worth doing one final inspection before taking the motherboard apart. Glad you found it!
Thanks! Finding it was a huge relief, and now I can finally get back to gaming.

If you don’t have a pickup tool, a screwdriver and a strong magnet can usually do the job.