Sidewayzracer 0 Newbie Poster

I just bought a used laptop and replaced the cpu that was in it making sure i got the right sSpec number. Well when i try and boot it up the power light comes on and the cpu fan turns on then dies after a second or 2. And there is nothing on the screen i tried hooking it up 2 a monitor and got nothing. Im not sure if a connection is off which shouldnt b a problem bc the CPU is easy 2 get 2 or if its a bad MoBo. or even a bad CPU . Also the cpu and heatsink start 2 heat up after a few mins