Hp g60 won't boot after motherboard change

Hi folks, really need some help on this one. Bought a second hand g60 that needed a couple of bits. I have fixed those bits and took the hard drive from my own broken g60. Now this computer was in bits when I got it but have tried the following

The power button trick
Swapping around ram
Taking out hard drive
Checked all cables and connections
Tried just taking the motherboard and fitting it to my g60

I get the battery light on but nothing else at all no noises or lights.

I am thinking motherboard but dont want to go shouting for my money back incase I have missed something.