All, This issue started with 11.04, I upgraded to 11.10 this week in hopes it would correct it, but after a few days it happened again.. A few times a day, randomly, my monitors will go black and the machine will come back in the post screen and boot up again. Sometimes it boots up properly, sometimes it boots to disk scan (I understand why...the machine just died with a bunch of stuff open) and sometimes it takes several cycles of this to come up. I connected to the system with my laptop and tailed dmesg, syslog, kern.log, and Xorg.0.log. I also ran a cat /proc/kmesg. Nothing is showing up in any of these log files when it happens..it's just like someone has pulled the plug. I just got through running 4 hours of the memory test with no errors. I have a AMD Phenom 9850 Quad-Core Processor and Nvida 9500GT graphics card. This system has been stable for like 4 years. I'm thinking it might be a hardware problem, but how do I find out? Thanks,