My desktop workstation has been encountering intermittent video issues, including illegible screen displays and cases in which the monitor doesn't respond at all after Linux is loaded. Rebooting the system always seems to fix it however. This isn't so much of a problem for me, as I have a vision impairment and use braille and speech output, but it is an issue when someone else wants to use the machine. The only relevant error I found in the kernel log is: Mar 20 15:05:58 jdc kernel: [23207.760016] [drm] nouveau 0000:40:00.0: DDC responded, but no EDID for DVI-I-2 (after turning the monitor off then back on, after which it still didn't display any video.) The video card in this machine has been replaced twice over the years, both times under warranty/service contract, and with the same model of card, so I have my suspicions. It's a very up to date Debian Sid system, kernel 3.2.0-4-amd64 #1 SMP Debian 3.2.39-2 x86_64 GNU/Linux I didn't find any relevant Debian bug reports. Obviously I want to know whether it's hardware or software, and if hardware, the card itself or something else.