xx5m1l3yxx

I use a fan controller in my system, (no idea what it is, too lazy to go look) and something I noticed is if it's turned down too low, the fan will not come on on startup, so your issue sounds voltage related (which has already been figured out), and you should be able to change it in the bios, ( which has also already been said ... I don't know why I'm repeating stuff) I would look for a fan mode set to silent and turn it off or up to something else.

If you signed into the PC with a Microsoft account before the swap and verified your account within settings, you should be able to essentially replace the old mobo pc within your microsoft account with the new mobo pc and activate it. So did you sign into the PC with a Microsoft account prior to swapping the mobo?