ATX PSU not powering up

#1

Hello,

I am attempting to power my new ROCK 5 ITX (v1.12 20240516) with a Corsair 1000W ATX PSU that I have previously been using with an Asus PC motherboard. When I plug everything in, and turn on the PSU, the CPU fan and PSU fan both spin very briefly and then stop. No video output or other indicators of life. This is where pushing the power button on my old motherboard would power everything up and boot the system. But tickling the power or reset pins on the ROCK 5 ITX gives no joy. It is my understanding from the documentation that the system should start up as soon as power is available. I suspect I’m either doing something silly, or I need a different PSU. Would just hate to buy one unnecessarily.

Does anyone have any tips I can try?

Much appreciated!

#2

I’ve read that some ATX power supplies require some minimum load on some of their output rails.

The Rock 5 ITX only uses the 12V rail IIUC. I wonder if the issue is your PSU is aborting the power up sequence when it senses no consumption on the 5V rail.

1 Like
#3

I think you are right. It is still able to power up my old PC motherboard and the Corsair documentation for testing your PSU says:

NOTE : Many Corsair PSUs have a zero-RPM feature that results in the fan only spinning for a moment after the PSU is powered on. This still indicates that the PSU is functioning normally.

I just ran down to the local computer shop and picked up a cheap PSU, the ROCK 5 ITX powers right up with it.

Thanks for you help!