Currently running an i5-3570K cpu, 16GB RAM, ASUS SABERTOOTH Z77 LGA 1155 mobo, Win7Ult 64bit, with an EVGA GTX 670 FTW card. Using a 3x monitor setup with a 27" 1080p main, 19" 1280x1024 secondary, and 42" 1080p TV as the third. The 2 monitors are using DVI cables, and the TV is HDMI.
This issue has happened 3x. The first time was pre-driver ver. 301.42, not sure exactly which driver. The main monitor suddenly stopped working, and eventually I got it running again by uninstalling the nvidia drivers and rebooting, and reinstalling.
The 2nd time, the main monitor stopped working again, and (was using 301.42 for sure this time) I ended up having to: uninstall drivers, unplug the 2nd monitor and tv, reboot, it then detected the main monitor, reinstall drivers, shut-down, plug in other monitors, and it was good to go again.
NOW, the main monitor stopped working again, and neither of the above solutions are working. I got to the point of following the 2nd solution thru to rebooting with one monitor plugged in, and THIS time, it doesn't matter which monitor I have plugged in, it will detect it until I plug in the 2nd one, and then the one goes dead. Not always the main this time either. I swapped cables/ports so that the main was now in the port the 19" was in, and it will now detect the 27", but not the 19".
I have determined it is not a bad port on the vid card either b/c I can shut down, swap ports, and it will still boot up just fine, but will not detect the 2nd display. The TV on the HDMI port is not affected, and seems to always be found with no issues. This is frustrating in the extreme as I'm sure you can imagine. Gotta be driver problem? Or is it something obvious I'm just missing? Suggestions would be appreciated. Thanks.
More about :gtx 670 suddenly detecting 3rd display
Update: the system is now detecting the 2nd monitor, and posts to it while booting, but as soon as I get into windows, it switches to the main monitor, and then won't detect the 2nd monitor again, but shows the main and TV available in nvidia control panel. ANY CLUES? Driving me nuts.
only thing I could think would be to contact tech support, and keep trying to work with different drivers. Have you tried the latest beta version driver? I had a similar issue, and am now starting to have a similar problem to what you are having, the last time I had the problem involved different cards, it just seems that multiple display setups are not given very much support at all as we're probably the least common demographic when it comes to PC setups. So you basically just have to keep on plugging in order to get a setup that works, then you're usually only going to be solid for months, until something minute happens which causes you days of hassle in order to get things stable again. My latest problem, was uninstalling IE9, and reinstalling it... how this would cause my displays to not detect, I have no idea. After I reboot, my main (a 50" plasma tv) no longer is set as the main and doesn't even show up, however when I pop the cable out then back in it magically reapears, however EVERY time I reboot it's doing it... so... back to uninstalling the driver and reinstalling it... YAY!
Totally forgot about this thread. O.o ANYWAYS, long story short, I ended up contacting EVGA support and they basically had me unhook all my displays but the main one, uninstall drivers, use a driver sweeper program to clean all old installs, and reinstall current drivers (forget which ver. at this point), then hook up other monitors, and set up multi-display. Works like a charm now, glad noone else had this issue.