This Question may sound familiar, but I really need a detail answer.. Here's how my G5 acts. (2G Dual) Pushing power button just gives me double click sound and power light above power button just flashes when I press it. No solid light. Nothing happens. No fan sound. Battery on logicboard seems fine. I checked it with voltage meter, which showed3.7 volts. PMU reset (I bought it before 2004) doesn't solve the issue. I removed rams and video card and tried to boot, nothing happened. Checked power cable and power outlet, everything is fine except G5. Nothing has been installed recently. I used the G5 yesterday and it was working fine. I shut it down for an hour and boot it up to work on my music, but it's been acting like this since. I'm so worried about contents and programs in this computer. I know I have to take it to apple shop, but I really like to know what's is wrong with it. Logicboard? or just bad battery? I hope it's the battery or power supply.. Has anyone had this problem? What was the cause? If anyone has experienced the same issue, I would like to hear it. Thanks.