PC won't boot into Windows since I installed a new AIO cooler

[vortex1]

I have just installed a Deepcool Mystique AIO cooler for an Intel i7-14700K. I have a Z790-A II motherboard.

The AIO powers on ok, and the radiator fans are spinning ok. I'm pretty sure I didn't disrupt any other cables during installation.

The PC will not boot into Windows - just a black screen after powering on.

I think oddly, there are no Q-LED warning lights on the motherboard whilst the screen is black.

I can get into BIOS usually after I've hard shut down with the power button and powered on again.

Not sure what to do to get the PC working again.

I have downgraded to an older version of the BIOS but that didn't work - same issue.

[vortex1 · Accepted solution]

Fxed!

Tried a Windows Automatic Repair - it came back it couldn't fix boot.

Went to this website: https://helpdeskgeek.com/windows-11/what-to-do-if-automatic-repair-couldnt-repair-your-pc-in-windows...

Went to this section:

5. Once you have Command Prompt up and running, enter the following commands one by one:

   bootrec.exe /rebuildbcd

   bootrec.exe /fixmbr

   bootrec.exe /fixboot

   When I typed in the 3rd command, it came back as 0 Windows Installations Found.

   I then opened up the PC case and reseated the boot SSD. I also replaced the Arctic Thermal Pad because I think that was a bad one, and put on the stock thermal pad. Checked the GPU cable, then put the PC back together and re-booted. This time it booted up in to Windows.

   Everything seems ok for now..the AIO is working nice, now that I've installed and setup the software for it. Just gonna have to install the latest BIOS again and sort out the BIOS settings. I will need to run Cinebench R23 to test if my AIO installation is sound (temps) when the CPU is pushed.

[vortex1]

Spoke too soon! This problem still persists. I've narrowed it down - it appears to be a power to monitor problem.

I have tried literally everything to sort this problem.

I have just ordered a more powerful PSU (1200w) as opposed to the 850w one at present. I think I have quite a lot of power hungry components and peripherals, so that might fix it. My thinking is that the AIO broke things power-wise, because it does need a sata connection straight to the PSU.

Afterwards, I am also going to clone my C: boot drive and swap the existing one out with a brand new one.

That should sort the issue. If not, I will totally wipe the drive I'm fitting and re-install Windows from scratch - in case anything adverse might be on the system I clone. Luckily I have backups of my files, folder, applications & browser bookmarks.