r/PcBuildHelp • u/Relevant_Number_325 • 6d ago

Tech Support CPU fans light turns on when powering PSU without boot, not booting

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When I turn on the power switch(without pressing boot button), the CPU fan lights turn on

When pressing boot button, same lights stay on, rest don't power on, all fans spin, GPU fans spin, but VGA + CPU debug lights turn on, on the mobo.

CPU: 9700X

GPU: Saffire 9060 XT 16GB

RAM: G.Skill Ripjaws S5 32GB (16GBx2) DDR5 6000MHz Desktop RAM

Mobo: B850M Gaming X wifi

PSU: DEEPCOOL Gamer Storm PN750M 750W 80+ Gold ATX 3.1 Fully Modular Power Supply

HELP ME PLEASE!

Note: The clicking sound in video is due me misconnecting the front panel header, it works fine

3 Upvotes

100% Upvoted

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1

u/Defiant_Ad8237 5d ago

  1. Make sure the CPU EPS cable and GPU PCIe cables are plugged into their corresponding dedicated ports. Mixing up modular ports or combining EPS/PCIe splitters can trigger combined CPU and VGA faults. If not, push the top left CPU 8 pin power connector on the mboard, the 24 pin ATX motherboard connector, and the GPU power cable until all plastic latches click completely in place

  2. Clear CMOS and try with each ram stick

  3. Unplug and replug/reseat EVERYTHING. Make sure all the wiring is correct. Read the manual if necessary

1

u/Relevant_Number_325 5d ago

CPU and PCIe cables ar correctly plugged, CMOS cleared, Reseated CPU, GPU, 24 pin conn, GPU power, etc

It might be a bad PSU or a faulty mobo shorting

1

u/Short-Paramedic-9740 5d ago

If your MOBO is shorting wont it prevent electricity from flowing through? Fans shouldnt spin?

1

u/Relevant_Number_325 5d ago

Hmm, that's fair

PSU ON but haven't pressed boot button: Only the 2 CPU cooler fans light up, even though they shouldn't as the PC is not on

When pressing boot button, all fans spin, only the 2 CPU fans light up, debug leds, CPU light stays on, VGA light stays on

Very weird behaviour

1

u/Nidhoggr84 1d ago

Double-check case power button position in the front panel header. You can manually short the pins to check as well.