So I just got my new rig all setup and going, and at first alls it did was shut off about 1 minute into trying to install the OS, or being the BIOS. Now it just beeps one lonnnnnnnng, beep until it either shuts off, or I turn it off. Now, it does POST, and I can get into the BIOS for some time. So, please, tell me what I should do! This iMac is driving me nice, lol.

I'm no expert on post code, but I've had a system do just 1 long beep before... it was because I didn't have the pcie plugs connected to my gfx card.

Iain:

Now it just beeps one lonnnnnnnng, beep until it either shuts off, or I turn it off. Now, it does POST, and I can get into the BIOS for some time. So, please, tell me what I should do! This iMac is driving me nice, lol.

Hi lain. Among other things, A long beep could indicate a fan-fail warning or a system overheat warning, or both! Open the case and make sure all of the fans are spinning. Next go into the BIOS and search for any fan-fail or overheat warnings (I am not familiar with iMacs, and not all boards have this option). While you are in the BIOS take a look at the CPU temperature and make sure it isn't running too hot. Post back here and let us know what you found!