I have a tough one regarding an iMac G5 ALS 17" 2Mhz I am fixing. First I want to point out that I am familiar with the innards of these ancient beasts as I have fixed a couple 1st gen iMac G5 as well as iSights and Duos. When I plug in the cord in the PSU, the 1st diagnostic LED comes on but when trying to start the computer the second diagnostic LED comes briefly on and then goes off. Nothing else happens, no chimes, nothing. According to Apple KB this is the sign of a faulty PSU. Yet, I have tried replacing the PSU and I get the same result. Now the weird part is that if I unhook the LCD cable the computer starts normally (it chimes) with the display off. What is most puzzling is that it will start with the inverter hooked up but the LCD display cable off but will not start with the inverter entirely taken off but with the LCD cable on. It seems that it is the LCD itself that prevent the computer from starting. I thought the inverter would draw current but not the LCD itself so it's probably something else. Anybody had anything similar happen to them? Could it be that the inverter is faly but it only draws when the LCD is hooked? Could it be some kind of short in the LCD or something that make it draw even with the inverter unhooked? All thoughts, comments, ideas welcome. Thanks in advance G.D.