Question PC Boot Issue: Dark Rock 4 Fan Stops, Black Screen, System Unresponsive

[Farien__]

Hello everyone,

Recently, when I turn on my PC, my Dark Rock 4 fan cpu spins for a few seconds and then stops. As a result, my PC doesn't boot up and stays stuck on a black screen. It powers off immediately when I press the power button (I don't need to hold it down for three seconds).

I’ve tried unplugging and replugging everything, and in those cases, I face the same issue with the CPU fan. However, the PC does manage to boot, even with the CPU fan not spinning.
All other case fans are working perfectly fine.

Where do you think the issue could come from? What should I try to fix it?

Configuration:

• be quiet! Dark Rock 4
• GIGABYTE B550 Gaming X
• AMD Ryzen 5700X
• 32GB DDR4 RAM (3600 MHz)
• NVIDIA GeForce RTX 4070 Ti
• be quiet! Pure Power 12 M (850W) 80 PLUS Gold
• be quiet! Pure Base 500 Case

 

[Colif]

Do you have latest bios on motherboard? link

guess it be hard to update anyway when its like this.

so bios can recognise the fan is there but it doesn't spin it up? what header on board is the CPU FAN running off? some boards will boot even if the CPU_FAN header is empty

my aio fans stop at startup until windows starts and then they start. I have to watch them just in case one day they don't start up.

try removing some ram and boot with 1 stick in?
I found this, same story but it appears he bought new parts to fix it - https://forums.bit-tech.net/index.php?threads/pc-wont-boot-boot-after-new-cpu-cooler.221071/page-2

how old is the cooler? I assume fan doesn't make any noises when running that would indicate its the problem

 

[Farien__]

Hello,
Thank you for the response. I updated the BIOS, unplugged and re-plugged everything, and it worked for 2 weeks.But this morning, the same issue occurred again...
I unplugged everything again, changed the thermal paste, and it’s working now...
I think it's a motherboard issue, where it doesn't detect the CPU temperature (-55c).
The CPU cooler is only 2 years old and doesn't make any noise.

 

[Colif]

This could be a long shot but it might be it...
do you use a display port cable?
tried using HDMI or another DP cable?
Swapping fixed it for a few people - it is a common answer to problem.

The issue is that DisplayPort has a pin (pin 20) designed to power adapters and whatnot, which would otherwise require external power to work. Due to this, standard VESA-complaint cables are not suppose to have pin 20 connected, because otherwise it would create a short between the source and the display.

This issue (DP pin 20) is actually well documented and somewhat common, but because the issues it can cause can manifest in various ways, unless you know what you're looking for you are unlikely to find it.

See link

I have an Aorus X570, can't say I seen this before, but it seems to be a Gigabyte bug with the B550 model. But it can happen in others.