I've been having an issue with one of my employees. He's using an HP Workstation that has an NVidia Quadro NVS 450 manufactured by HP. Great graphics card that should support 4 monitors. In fact it did, until a few weeks ago. The 4th monitor started flickering, so I unplugged it and plugged it back in and the computer no longer recognized the 4th monitor. I've since tried the following:
Replaced the monitor - no effect.
Plugged his monitor into my computer - His monitor works fine.
Tried different cables - No effect.
Tried plugging the monitor's power cord into a different outlet - No effect.
Tried plugging monitors into different ports on the graphics card - no matter which ports, I could get 3 monitors to work, but NOT a 4th.
Updated drivers for the graphics card - no effect.
Updated firmware for the card - no effect.
Tried switching the graphics card slot - Still only 3 monitors get recognized by the computer, it's like a 4th doesn't exist even though I have it plugged in.
Installed an NVS Quadro 295 (so he has 2 graphics cards) - He now has the ability to plug in up to 6 monitors, but the computer STILL only works with 3. On the upside, it now recognizes the 4th monitor and says it's working properly (but it isn't).
This has been a big thorn in my side and I would greatly appreciate any help I could get!