I just got an RX 480, and I have two monitors that only have DVI-D inputs, so I also got two Displayport -> DVI-D cables. ( https://www.amazon.com/gp/product/B008DW5N2W/ref=oh_aui_detailpage_o00_s00?ie=UTF8&psc=1 )
When I boot up the computer I can use HDMI to an extra monitor I have, and I can use the DVI-D port with a normal DVI-D cable to either of my monitors, but if I use the DisplayPort ports, I do not get a signal.
Further, if I have one working monitor with the normal DVI-D cable, and then I try to add my second monitor with the DP->DVI cable, the computer will just power off shortly after the BIOS splash screen and not continue to boot.
I have found several posts in various places online about DP issues with this card, but most of them seemed to be driver related, or recommended power cycling the monitors. I have power cycle'd the monitors, but I'm not even getting signal for the boot up before it gets to Windows, so it doesn't seem to be an issue with drivers. I do have the latest drivers installed nonetheless.
Has anybody run into this or know how to resolve it?
Those DP to DVI-D cable have passive DP connection with 1920x1200 maximum resolution.
I think you need at least one active DP to DVI dual link adapter+DVI-DVI dual link cable.
Full model names of your monitors?