So here's my problem! I just got a new case, put everything in. Turn it on, all the fans start spinning and the led fans come on, but a few seconds later the system turns off.

Also by the way, the PSU doesnt fit in perfectly and i manage to get two screws in (not all the way) its hard to plug in. And the computer isnt connected to a monitor or anything at the moment

Any help?

P.S by the way, my psu is brand new and i have been using it for a week and used it an hour before the case change.when you swapped mobo to second case , did you notice any small plastic washers in bottom of old case , these are used to insulate Mobo from stand offs .TRY removing mobo from case and try it on an insulated surface as proof this is troubles
Small plastic standoffs? I cant see any. Only metal things that sick out and have a place for screws to go in, which i am UNABLE to remove (for i am probably too weak...). also i DIDNT get to use every screw slot on the MOTHERBOARD because i didnt have enough 'metal things that stick out'. check the stand off are in the right position in new case or they can short out the board and stop it working, use a pair of pliers and use the ones from old case if necessary but DONT add any extraIts fixed! i believe the mobo connector wasnt plugged in properly or either the heatsink or something. Thanks for all the help guys!