So, my computer is back to not booting and beeping continuously - I already ordered a different mobo (ASUS Z87-K) and will try to return this one and hopefully get a full refund. They may only agree to exchange it but then I'd just try to sell it and in the unlikely case that I install the ASUS mobo and find the problem was not being caused by the mobo in the first place, I have two weeks to return it without giving reasons, according to Czech law.

This unfortunately means that my plans for working on Empire this whole weekend are f*cked.