Just realized most people don't test PSUs before swapping parts

I was helping a friend in Denver troubleshoot his PC last week. He had already replaced the motherboard and GPU but it kept crashing. I asked if he tested the power supply first. He looked at me like I was speaking another language. I grabbed my $30 PSU tester and found the 12V rail was dropping to 11.2 under load. Saved him from buying another useless part. Has anyone else run into people skipping the obvious first step?

2 comments

2 Comments

nina_johnson861mo ago

I mean that's wild to me. What did he say when you showed him the voltage drop? I'm curious if he even knew what a 12V rail was before you pulled out the tester. Maybe it's just me but I feel like so many people jump straight to 'replace the expensive stuff' without checking the cheap stuff first. Like yeah a bad PSU can wreck everything, but testing it takes five minutes. Did he end up keeping the new motherboard or was he able to return it?

troythompson1mo ago

Hold on there, I'm gonna play the other side of this. I've built plenty of rigs over the years and honestly, I can count on one hand how many times a PSU was the actual culprit behind crashes or weird behavior. Most of the time it's driver issues, bad RAM, or a CPU that's not seated right. Putting all your faith in a cheap $30 tester too, those things can give false readings or flat out miss problems. I've had testers show stable voltage on a PSU that later blew a cap and took a mobo with it. Plus, if his machine was crashing constantly but still turning on, that's not always a dead giveaway for a bad power supply. I'm not saying never check it, but I get why people don't make it their very first move.