My mom won a Gigabyte 750W 80+ Gold power supply from an auction site for about $10. The site reportedly resells customer returns, so I have no idea how it was handled or whether it was ever used. Since a faulty PSU could damage other components—or worse—I don't want to connect it to my main PC just to see whether it works. The unit includes all of its cables, and some still look factory-new. The model is rated C+ on a PSU tier list, and it isn't one of Gigabyte's previously recalled or notorious failure models. Is there a safe way to test it, and would you trust a returned PSU like this?
4 Answers
Personally, I’d avoid using a returned PSU unless the savings were truly worth the risk. A power supply can fail in ways that damage the motherboard, graphics card, or other components, and a new reputable unit is usually inexpensive compared with replacing those parts. It’s also not worth the safety anxiety.
You can test a PSU without connecting it to a computer. Use a PSU jumper or the correct paperclip test to start it, then check the main rails with an inexpensive PSU tester or a multimeter. This can reveal obvious voltage problems before the unit is connected to valuable hardware. Keep in mind that a basic tester won’t detect every possible fault, so passing the test doesn’t guarantee the PSU is reliable under load.
First, identify the exact model number and check its reputation on a current PSU tier list. A C-tier unit isn’t automatically dangerous, but it’s not something I’d choose for a high-end build. Since you have all the original cables, that’s a good sign—never substitute modular cables from another PSU, because the pinouts may be different. Also confirm that it isn’t one of Gigabyte’s older models associated with serious failures.
I checked that already, and it isn’t one of the problematic models. All the cables are included, and a few still appear to have their original factory twist ties. The model is listed as C+.
Used PSUs can be fine when they’re known, quality models with a documented history, but an auction return has an unknown history. If you decide to try it, inspect it for damage, burning smells, loose parts, or a noisy fan, test the rails first, and only use the cables that came with it. For a main system, though, I’d still lean toward buying a new, well-reviewed PSU with a warranty.
That’s my thinking too. Saving money on the PSU isn’t worthwhile if it potentially destroys the rest of the system or creates a fire hazard.