Watch out for those cheap power supply testers from online marketplaces

Had a client bring in a gaming rig that kept shutting off under load. Figured it was the PSU, so I grabbed this $15 tester I got from a big online marketplace last month. It showed all rails as good, green lights across the board. Spent the next two hours checking the motherboard, RAM, you name it. Finally, out of frustration, I hooked up my old but trusted multimeter. The 12V rail was dipping to 10.8 under a simple load test, way out of spec. The cheap tester was completely lying. Learned the hard way that those things can't simulate a real load. Has anyone found a budget-friendly tester that's actually reliable, or is a multimeter the only real way to go?

3 comments

3 Comments

eric_murray269d ago

Feel your pain on that one... wasted a whole afternoon last year on a similar goose chase with a "good" reading from a cheap tester. It's frustrating how those little green lights give you such false confidence. Honestly, I just keep a basic multimeter in my kit now for any real diagnosis. Those testers are okay for a dead/no power check, but for anything under load, they just can't be trusted.

danielw888d ago

Wait, you actually trusted one of those little light-up pens for a real job? That's wild. Those things are basically fancy sticks that tell you if you're about to get shocked, not if a circuit is working right. A whole afternoon is brutal, but honestly not surprising. A real meter is the only way to go once you move past "is this wire live or not".

joseph_adams661d agoMost Upvoted

Seriously, what's the worst failure you've seen from trusting one of those pens? I've heard stories about them showing power when a circuit is dead, which is just dangerous. Makes you wonder why they're even sold.