Question PC won't turn on after fan swap

Feb 23, 2023
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Specs:
CPU: i5 12400
Mobo: Gigabyte H610 H DDR4
RAM: G.Skill Aegis 32GB 3200 C16
GPU: STRIX 6900 XT LC Gaming TOP (XTXH)
PSU: Silverstone DA850-G

The GPU has a 240mm AIO attached: View: https://imgur.com/a/x2vaJck


I bought a pair of Noctua NF-A12x25 fans to replace the rad fans. I hooked everything up, plugging the new fans into the exact same connector coming from the GPU that the stock fans were. I press the power button and the PC turns on for half a second before turning off. I haven't been able to get it to turn on again since.

I hooked up the bare minimum to get the pc to work. Only the motherboard, ram, cpu, 8 pin EPS power, 24 pin ATX, and a HDMI cable for video out. Nothing happened when I shorted onboard power pins. I disconnected the power supply cables from the motherboard, then shorted the 4th and 5th pins on the 24 pin cable to see if the power supply would turn on, and it did. So I think it's the motherboard. But I'm not 110% sure. Also, a friend suggested hooking up an old (nothing important on) hard drive to see if it would turn on, and it did, the platter spins.

Anyone have any advice?
Thank you
 
Disconnect Noctua fans. See if system turns on (obviously don't put much load on GPU), if it does try connecting Noctua fans one at a time to motherboard header to see which one is faulty. If the system does not turn on without Noctua fans connect original GPU fans, if that works this probably means GPU needs specially wired fans to work.
 
Feb 23, 2023
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Right now there's zero fans connected whatsoever bar the one on my CPU tower cooler. Absolute bare minimum to see if it will post at the moment.

CPU
Motherboard
RAM (Have verified not the problem)
8 pin EPS
24 pin ATX

No life whatsoever.
 
Right now there's zero fans connected whatsoever bar the one on my CPU tower cooler. Absolute bare minimum to see if it will post at the moment.

CPU
Motherboard
RAM (Have verified not the problem)
8 pin EPS
24 pin ATX

No life whatsoever.
You mean even without GPU? In that case indeed something died, and if the PSU works then it must have been motherboard. Though I find it strange that it died because of GPU fans as those have no direct connection to motherboard power at all. Maybe just coincidence.
 
Feb 23, 2023
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You mean even without GPU? In that case indeed something died, and if the PSU works then it must have been motherboard. Though I find it strange that it died because of GPU fans as those have no direct connection to motherboard power at all. Maybe just coincidence.
Even without GPU yeah. HDMI cable plugged into onboard graphics. Nothing happening. I just plugged in a USB hub with an LED light on it to see if it would light up when plugged in, and it does indeed light up. Still sound like motherboard?

If so, I can order a board tomorrow and have it Thursday. See what happens then. If it's not the problem, I'll send back the board.