I was putting together a computer for a friend, and everything was working fine the first time I plugged it in. Then I took it all apart again because I decided to screw down the motherboard differently. Then when i reconnected everything, the CPU fan wasn't working. I never unplugged it during the whole process. I know its the slot, because the fan works when plugged into the northbridge slot. What the hell can I do? Is it safe to just plug it into the nb slot? The motherboard is a MSI KT880 Delta model ms7047 version 1. Help?