280R Crashing

I have a 280R that now crashes whenever I disconnect the null modem cable from the serial A console port. This is a new behavior. This did not occur approx. 3 weeks ago when I installed Solaris 10 6/06. The server has been running until last week when I noticed it was down (could not be pinged on any interface). If I boot the system from my laptop connected via null modem cable, and leave everything connected, the system remains stable and runs fine. I even tried to fool it by syncing the disks, halting the system, powering it off, disconnecting the cable and powering it back on. Nothing doing. It would not even boot.

Any Sun hardware wisdom on this would be greatly appreciated.

[701 byte] By [golfbravo] at [2007-11-26 9:37:47]