O.K. HERES THE DRILL...... I have a mac that was given to me cuz I cant afford to buy a new one....poor me, anyway Im not familiar with macs so the info I can give you about this machine right now is very limited guys. As far as I know this is a apple power macintosh g4 m5183 desktop. Now when I plug in the power cord and hit the power switch....no sound no fan ....nothing at all. I'll be honest I cant afford apple tech support...they want a million dollars a minute. I tried to use the "pc way of thinking" and Im guessing that maybe the psu is bad or maybe the onboard battery. Again I really am not familiar with mac technology so in order to help me you will have to tell me where to look to provide you the info....Now I can get inside the case no problem...By the way the onboard battery is a "TADIRAN 3.6 VOLTS HIGH ENERGY LITHIUM SIZE 1/2AA BATTERY" (If you knew how much to replace one of those , if needed that would also be a plus)