I just got a new logic board for my 700 MHz iMac g4 (one of the pins on the old one bended, airport slot went bad, heatsink came off...) but when I plug the new one up it won't give me the "bong" sound or power the monitor. Any ideas? The harddrive will spin and I think it is loading the operating system (just what it sounds like). The ram is good. Thanks in advance. PLEASE PLEASE, help! I need this computer.