When I tried to turn on my PC, it suddenly made a very loud popping sound. The RGB lights still come on, but the system shows no other signs of life and doesn't even reach the BIOS. I suspect the power supply, since it's the oldest component and has accumulated quite a bit of dust, but I can't see anything obviously burned or damaged. I'm also hesitant to open the PSU because it may still hold a dangerous charge, and I don't currently have a spare unit to test with. What should I check, and is replacing the PSU the safest next step?
2 Answers
A loud pop often points to a failed capacitor or another component inside the power supply. The fact that the RGB still works doesn’t rule it out, since the lights may be powered by a rail that survived while the main output failed. Don’t open the PSU—capacitors can remain dangerous even when it’s unplugged. The safest test is to use a known-good replacement PSU or have the current one checked with a proper tester. Given its age and heavy dust buildup, replacing it is a reasonable first step.
It’s worth checking the motherboard and other components for obvious damage, such as bulging or leaking capacitors, cracks, scorch marks, or a burnt smell. Also inspect behind the motherboard for any loose conductive debris that could have caused a short. However, components can fail without leaving visible evidence, so a clean-looking board doesn’t eliminate the possibility of damage. Avoid repeatedly trying to power it on until you can test it with a known-good PSU.
The motherboard is only about a year or so old and looks clean, while the power supply is much older and has a lot of dust buildup. I’ll still inspect the board carefully, but the PSU seems more likely.

I’m trying to find a replacement, but I don’t have another PSU available right now. The current one is also the oldest part in the system, so that makes it my main suspect.