Asus m2n-sli deluxe shuts down when internet disconnect

[rickityrickets]

Hello,

My old homebuilt athlon 64 x2 on asus m2n-sli deluxe with 4 GB RAM and Win 7 has developed a strange behavior. The power supply shuts off cold if I disconnect the ethernet connection from the internet. If I try to start it with ethernet disconnected, it won't power up at all. Any attempt to enter bios setup causes shutdown about 10 seconds later. I flashed the bios to most recent - no joy. Bought used replacement MB - identical problem.

Anyone have any thoughts?

 

[o1die]

Check for a backplate piece that's touching the lan area if you didn't break it off. Make sure the backplate is square; if not, remove the board and press on the corner that's not. If you remove the board, double check the case standoffs to be sure none are touching circuitry or there's any loose screws underneath the board.

 

[rickityrickets]

Check for a backplate piece that's touching the lan area if you didn't break it off. Make sure the backplate is square; if not, remove the board and press on the corner that's not. If you remove the board, double check the case standoffs to be sure none are touching circuitry or there's any loose screws underneath the board.

Great thoughts, but no cigar. I've tried it with IO plate completely removed. No loose screws and all standoffs are correctly positioned. I've also tried it with all peripherals removed, including the hard drive array and the raid controller card. Tried it with the ethernet connected to a switch that was NOT connected to internet - it fails in this configuration. But, as soon as I connect the switch to the router, I'm back in business.

Anyway, thanks for trying.