Jason White <jason@jasonjgw.net> writes:
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
FWIW... IIRC EDID (and DCC?) are the way the computer asks the monitor "hey, what resolutions do you support?" -- they are the reason we don't need to manually specify modelines in xfree86.conf anymore. If it can't talk EDID to DVI-I-2, I would expect a monitor plugged into it to either get a generic "hopefully works anywhere" VESA mode line 800x600. I once had an LG 2010 LCD monitor where over DVI-D, EDID worked fine, but over D-sub, it negotiated an incorrect modeline. I worked around it by manually specifying a "2048x1024twb" type modeline each time I connected the laptop to that monitor.
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.
Assuming there's nothing in Xorg.0.log either, I would next check xrandr's output to see what modelines it knows about. If you have a computer that works correctly with that monitor, or a monitor that works correctly with that computer, you should compare with its xrandr.