How to tell if a graphics card supports two monitors

With AMD 5000 series graphics cards, at least one of the 3 monitors must be connected through DisplayPort. A single card can only provide up to 2 traditional (VGA/DVI/HDMI) connections simultaneously. DisplayPort is a different technology that allows more screens to be connected. If none of your monitors have a DisplayPort connection, you will need an active DisplayPort adaptor, such as one of these. A passive DP adaptor will not enable your 3rd monitor.

Hm. From my understanding, you are attempting to connect two monitors to your new discrete card and then use that to manage displays.

If your BIOS outputs to both monitors (which it should, since that seems to be the default with more modern boards), then that confirms that everything is working. In that case, I cannot offer much advice beyond cleaning out the connectors between the monitor, adapter, and video card itself. As well, ensure that Windows is recognizing the monitors in the first place. Either check the AMD Catalyst Control Centre, Windows Screen Resolution configuration, or even check Device Manager to see if they show up. I'm not sure if they show up in device manager, but I do know that Piriform's Speccy does show connected monitors, so I imagine Windows device manager does as well.

However, if your second monitor is completely dead, I would look into checking for hardware failure on the monitor, the video card's DVI port, the adapter, and any cables in between. I personally would replace the adapter, since they seem to have the highest failure rate in my set-ups. As mentioned above, I would still definitely try to clean out the connectors to make sure there isn't a piece of dust in between. But first, you should try replacing the first monitor with the second ("dead") one to see if it even works at all.

While I hold a little doubt the hardware is at fault here, it is entirely possible.. unless you mentioned that "the monitor outputs" somewhere and I missed it.

tl;dr

• Check AMD/Windows configuration
• Clean out the connectors
• Swap out the monitors if the second one doesn't output at all
• (No system POST on the monitor at all) Replace the adapter, cables, etc. to see if they're the fault of the problem.