iMac a 1208 Does not power on

Ive had my iMac 17 for some time now. A week ago we had bad electrical storms in my area and when i came home the imac was off and i can not get it to power on after following the basic trouble shooting on the apple website.

When i flip it over and take off the memory bay cover. i can see a green light on the inside when connected to a power supply.

How can i best trouble shoot further? id like to attempt to fix it if possible before giving up and buying a new one.

THanks

Imac a1208