KV8-MAX3 7f hang?

Hoping someone can help. I've got a KV8-MAX3, it had been hanging intermittently and finally wouldn't boot the other day. I popped open the case and found that the Northbridge fan had burnt out. I replaced the fan and am still having the same issue. The computer comes on, displays the Abit splash screen and just sits there. The board displays code 52 which I believe is a memory check. After close to five minutes it proceeds to a 7F and displays a screen that says CMOS checksum error, defaults loaded. Asks you to push F1 or delete. The system doesn't repsond to any key presses. I have tried clearing the cmos, replacing the battery and pulling memory modules. I'm out of ideas here!

Thanks in advance!

Figured it out, turns out my ipod nano was intrerfering with the boot process. thought I had disconnected everything but what I thought was the mouse was my USB hub..god bless apple.