I press the power button and my quite new macbook (Leopard) is beeping "SOS" (short-short-short-long-long-long-short-short-short) , the LED in the front, right, is blinking - this ist repeating until I turn it off by pressing the power button for a longer time. What happend?
Same thing just happened to my late 2007 iMac. Got a brief power failure in the middle of EFI update. Beeps SOS (3 x short, 3 x long, 3 x short). Screen stays off, keyboard has no response (caps lock key doesn't turn on). Can't boot from the recovery disks either.
Used the Apple EFI Resoration CD 1.1.6 right now. Seems to work. But the manual is a little wrong, when you hold the power button when powering up, it won't work. Just power on, insert CD.
http://docs.info.apple.com/article.html?artnum=303469
Restoration successful. Updated EFI normally after that. Works fine now.