Answer to: PSU and Video Card DiagnosticsI am in the same exact spot as you. I just sent the video card to be "repaired'. It cost me $100. The original problem was when I powered on the IMAC I got the white screen and could hear the chime. I ordered 2 different brand new LCD screens, both gave the same white screen so I sent them back and sent the video card out. Now with the "repaired" video card when I power it on I get the chime with a BLANK black screen and when I plug in an external monitor to the mini DVI connector I get nothing there either. I'm losing my mind with this thing. Let me know what happens when you put in your new power supply.