How is iced coffee bad? If done right it is just normal coffee but cold. On the other hand, cold brew almost always has a slight stale oil taste which I can't stand.

I had a similar experience before. I tried swapping a i3-2120 to a i5-3300 on a cheap Asrock H67 board. I have installed the latest BIOS and support page said it should work but it just kept blue screening.

It was fixed after I replaced the MB to a slightly less cheap H77 board.

Friend who helped me fixed the computer said that MB manufacturers don't really test their MBs with all the CPUs they support. Some niche CPUs may not work, even though they are supposedly supported.