Good morning everyone! I've been searching the web all morning to see if anyone has had any similar issues like this but so far no luck, hopefully someone might be able to help me identify my problem. My iMac (Early 2008, 24", 2.8 C2D, A1225, ATI Graphics) has recently been on the clutz recently. I completely wiped the HDD to start from scratch on OS X 10.5 and it has still been having the issue. The issue is that once I press the power button I can hear the fans, HDD and CD drive spinning but nothing comes up on the display. I checked the diagnostic LEDs and only the first 3 LEDs are on (#4 Stays unlit). I tried resetting PRAM but it does not read my USB keyboard at this state (mysteriously it only reads the USB mouse not connected to the keyboard's USBs). There is no chime/dong when I first press the power button either only whats stated above. After I leave it at this state for about 2hrs it finally bongs and starts up normally, works without a problem and all 4 diagnostic LEDs are now on. I can restart it with no problem but if I select sleep or shut down it'll go back to the fans and HDD only with nothing on the display. Can anyone help me out with this issue? I am really hoping it's not the logic board or something big but any input in appreciated. Thanks! I should add that since I does not read my keyboard inputs until it actually bongs I cannot boot to CD or any other keyboard combinations since it will randomly bong after ~2hrs of it sitting in the black LCD but powered on state. Even after taking out the RAM it would just sit there and also when the HDD was without an OS it would also just sit there with a black LCD (diag. LED #4 off) until finally after waiting the typical ? Folder icon would show up.