Question My pc won't start after changing CPU and installing liquid cooler

[xarthas]

Hi,

I installed a new processor (5800x3D) on my motherboard (ASUS Prime B450M-K) then plugged the water cooler (Masterliquid ML360R RGB) on my CPU. I installed all the parts then started windows 11. It booted finely. I used CPU-Z for bench and stress test. Everything seems okay. When the processor works, pump is working. I hear the sound, fans star to turn faster, I feel the cold coming out from the radiator. Then I restarted computer. It boots again. I did the same tests without any issues. Then I removed the 3-pin cable I connected to 4-pin CPU Fan. Checked some others as well. Now my computer won't start. The screen remains in stand by mode, there's no power on keyboard & mouse either. Rams are working as well. Power is coming from PSU to motherboard, LEDs do appear to be working. Checked CPU cable goes to motherboard and PCI cable goes to GPU. They are correct. I started the system and booted windows but now something is not working. I also noticed that pump is also working when the PC starts. It doesn't make any sound. Is it the mobo, CPU or GPU? Any ideas?

 

[Tom cruise432]

Check to make sure the 24pin and 4 or 8 pin CPU power cables are inserted correctly. Try reseating the ram if it came loose when you were working on it.

 

[xarthas]

Check to make sure the 24pin and 4 or 8 pin CPU power cables are inserted correctly. Try reseating the ram if it came loose when you were working on it.

I checked the CPU cables and they are plugged correctly. Also switched RAMs and removed each other. Nothing changed.

 

[geofelt]

A processor will not start if it can not detect that a cooler is installed.
One way is to see if the cpu fan connector is turning a fan at 500 rpm.
I do not know the instructions for your aio, but I think the pump should be connected to the cpu fan header and the bios profile should have that connection running at 100%

 

[xarthas]

A processor will not start if it can not detect that a cooler is installed.
One way is to see if the cpu fan connector is turning a fan at 500 rpm.
I do not know the instructions for your aio, but I think the pump should be connected to the cpu fan header and the bios profile should have that connection running at 100%

The pump was working fine. But right now i cannot understand whether the cpu detects it. I always plugged the pump on cpu-fan. Radiator fans go to cha-fan.

PS: my gpu is working fine. I tested it on another pc