Can I activate the power source by connecting just a fan hub?
Can I activate the power source by connecting just a fan hub?
Yes, you can test the PSU by connecting it via a Molex cable to the fan hub alone, without linking it to the motherboard.
My initial reaction is no.
Further information is required.
Is there an issue with the power supply unit or the overall build?
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Please update your post with complete hardware specifications and operating system details. Also, clarify how components are connected. References, images, and more context would be useful.
Details are important.
You only need to touch a green wire with any black wire on the 24pin connection or harness—it's known as a paper clip test, though it's not accurate. Why? Because the test doesn't reveal how much power the PSU can actually deliver; it just spins the fan.
Why are you even concerned about testing a PSU? You should consider sharing your full system specifications, as my colleague requested, and if you're considering a used PSU, perhaps reconsider that choice.
Moved the discussion from the Cases section to the Power Supplies section.
In the past, I would link a substantial load to desktop PC power supplies, such as 12V 60W headlight bulbs, across the 12V, 5V, and 3.3V rails. Nowadays, I merely connect the ATX PSU to an older (often used as a backup) motherboard if I'm uncertain.
I acquired a low-cost digital "tester" that fits into the 24-way PSU connector and displays the voltages on all rails. I've only used it with some second-hand Corsair 850W PSUs that were given to me.
I think it's acceptable to test a modern ATX PSU using a fan hub, but I wouldn't advise doing so unless the hub itself is more than just a simple splitter. At the very least, link two or three fans to the hub to create a small load. Alone, without any fans connected, a fan hub is unlikely to draw more than a few tens of milliamps, or perhaps a few hundred milliamps if it has a digital display.
Another option is to connect a 3.5-inch hard disk to power both the +12V and +5V rails. Even in this case, most hard disks consume less than 8W when idle, so it shouldn't strain the PSU significantly.
With a brand new, high-quality PSU, I simply plug it into the new motherboard and power it on. My 7950X and several earlier builds handled this process without any issues.
This article, published eight years ago, outlines some reasons why older switched-mode PSUs might struggle when powered with no load. This likely refers to AT PSUs produced in the 1990s and early 2000s.
https://electronics.stackexchange.c...g-a-switched-mode-power-supply-without-a-load