Hello @Deimaginator, and welcome to the Community.
First, I would like to test whether the PC starts normally without that new fan.
If all drives are recognised in the BIOS, you may need to restore the default settings:
1. Press the F9 key to automatically load factory settings. A message appears asking you to continue this operation by selecting OK or cancel the operation by selecting Cancel. 2. Confirm the changes by selecting OK and then press Enter. The BIOS Setup utility window appears with the cursor on the first value in the window. 3. To save the changes and exit the BIOS Setup utility, press the F10 key.
Inform us if both steps do not solve the problem.
Kind regards,
EastClintwood
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