Observation of unusually sluggish PSU fan operation.
Observation of unusually sluggish PSU fan operation.
Hello. Recently I found a good deal on a used electronics site. I purchased six Corsair PSUs, each priced at 17 euros, while most places charge between 30 and 40 euros. After testing them all, they functioned perfectly except for one: the Corsair CX600M. The fan appears to be running a bit too slowly. Is this normal? Should I return this power supply? It might be operating in a low-temperature, low-RPM mode. I’ll attach a video for reference. I notice it behaves similarly in the video. By the way, I’ve also observed that it briefly increases speed before slowing down again, and there’s no airflow detected.
PSU images:
https://imgur.com/tPXqV6t
Video of the slow fan:
https://imgur.com/1mV3oZd
View: https://imgur.com/tPXqV6t
Video of the PSU's slow fan:
https://imgur.com/1mV3oZd
What are you anticipating from a 12-year-old PSU? It's been through many years, including the fan. Have you checked the ripples?
What is that and how can I check it? I'm not very familiar with electricity. I just connected them to a motherboard and plugged them in. I tested each one for about 5 minutes to see if they are working properly and not dangerous, but I plan to run a longer test later. Is this unusual behavior for the fan?
Ripple occurs when there is instability in the power rails. If you draw a graph of voltage versus time, it will either be perfectly flat or show some waviness (ripple). You can find examples online comparing new and worn-out PSUs. To measure ripple, an oscilloscope is required, which might be too costly to purchase here. Older PSUs tend to be less stable due to component wear and other factors.
At my workplace, the systems guy used old PSUs from CAD engineers' PCs in low-end office machines because it doesn’t matter much for just running Excel and PowerPoint all day. I think whether these PSUs are suitable depends on your specific needs.
Regarding the fans, some PSUs have a reduced or no fan mode when operating at low load to minimize noise. Check the specifications for that PSU to see if it supports full-speed operation. The fan may spin at full speed only after powering it up, which could indicate a controller issue or simply insufficient load to reach maximum speed.
[edit] Just a note: avoid using these in expensive systems, or better yet, don’t use them at all, since the situation can change depending on the history of the equipment. These units might have been pushed to their limits in a mining rig for years, so it’s important to assess the risk.