My mom recently won a Gigabyte 750W 80+ Gold power supply from an online liquidation auction for about $10. The site reportedly resells customer returns, but I don't know the unit's history. Since a faulty PSU could damage other components or become a safety hazard, I'm hesitant to connect it directly to my PC just to see whether it works. The unit includes all of its cables, and some still look factory-new. Its model reportedly receives a C+ rating on a PSU quality tier list. What's the safest way to check whether it's reliable, and is there anything specific I should verify before using it?
4 Answers
First identify the exact model number and check its reputation on a current PSU tier list. A C+ rating isn’t automatically unusable, but I’d be much more cautious than with a well-reviewed Tier A or B model. Also confirm that every cable belongs to this exact PSU—modular cables are not universally interchangeable, even between units from the same brand. It’s good that all the cables are included, but that doesn’t prove the unit is safe.
You can test it without connecting it to a computer. Use a PSU tester to check the main voltage rails, or use the proper ATX jumper method to start the PSU and measure the outputs with a multimeter. A basic tester can reveal obvious voltage or connection problems, but passing that test doesn’t guarantee the PSU is healthy under load. Don’t open the PSU enclosure, and stop using it if you notice burning smells, unusual noises, sparks, or unstable readings.
The safest choice is still a new unit from a known-good model line. Gigabyte has had some problematic PSU models in the past, so verify the exact model rather than relying only on the wattage and efficiency label. If you decide to test this one, test it outside the system first and make absolutely sure the modular cables match that model.
I specifically checked for the previously recalled or failure-prone model and it doesn’t appear to be one of them. I’ll test it separately before considering it for my main PC.
Personally, I’d replace it with a new, reputable PSU. A used or returned unit may have an unknown history, and the money saved usually isn’t worth risking your motherboard, graphics card, or other components. Power supplies are one of the parts where I prefer not to gamble.
That’s my concern too. Even if the PSU appears to work, a hidden fault could damage expensive hardware or create a serious fire risk.
I checked the model and it isn’t one of the Gigabyte units known for major failure problems. All the cables were included, and a few still had their original-looking twist ties.