If you have power to the motherboard, there will be a light on the motherboard, check. Remove all cards installed in any of your card slots (except for video if no built in is available), does it boot? If no, remove any fan headers connected to motherboard (except for CPU), does it boot? If no Remove all your memory, does it boot? if no, remove your CPU, does it boot? If no are all the power cables to the motherboard plugged in correctly? If yes, then your mobo is dead. If a motherboard is fine, removing memory and or CPU will cause it give you beep codes that tell you, hey, your memory or CPU are missing. If you get not codes, then your mobo is brain dead.