Hardware revision 1.05, new jumpers
Hardware revision 1.05 of the ASUS A7N266-VM motherboard includes some extra pins, including something labeled CHASSIS that sits between the SMBus connector and the PANEL pins. CHASSIS is a 4 pin set. If you don't put a jumper over the two pins at the edge of the board, then the BIOS interrupts the boot sequence and throws up a message stating something like "Case is open or cover has been removed."
There's nothing in the BIOS to control this ... Can't tell you what version of the BIOS I'm running, though, they might have updated it since they made my board.
The new pins and the BIOS behavior are not documented in the manual that comes with the board, or the manual on the ASUS web site, E1014A.
Additional stuff:
CHA_FAN pins, for powering and monitoring a chassis fan. Pinout is the same as the CPU_FAN pins. This is a good thing.
There's something different about the front panel audio connector pins (AAPANEL1). My motherboard had jumpers across some of those pins, which I removed, because the manual says nothing about putting jumpers there. Interestingly enough, the audio coming out of the back panel didn't work after I did that ...
To enable the rear audio output ...
On AAPANEL1, ASUS Front Panel Audio Connector,
jumper LineOut_FR to LineOutRR
and LineOut_FL to LineOut_RL
Again, I'm running ASUS A7N266-VM hardware revision 1.05.
Spiny