Disconnect everything off the logic board, keep only the magsafe power board connected and try again to power the machine from the two power pads. Plug headphones to the sound jack to hear the starting chime if any. If you still have no activity then the logic board is probably dead. You can buy a used one for about $200 (maybe less for a 2006 model) off ebay.
http://shop.ebay.com/i.html?_from=R40&_trksid=p5197.m570.l1313&_nkw=macbook+1181+logic+board&_sacat=See-All-Categories