My computer doesnt function right

Question

my computer fail to start one day. so i opened it up n everything seemed ok. i took out the cpu and it was bend so therefore i asumed it was the cpu. i order one and it started to work. by that i mean the power button lighted up and everything seems to work including my cd-rw tray. well when i turned it off and pluged the other components such as the monitor, keyboard and the mouse none of those things worked. i dont know what else is wrong so i really need help.