Describe your system:
Problem 1) - SOLVED
So all monitors have been tested (so the problem is not the monitors)
The 2x DP connections are fine.
The last monitor I have connected as follows.
GPU (HDMI) -> 2mtr cable -> HDMI 5 port switch -> HDMI to DVI into monitor
I am using a switch as I have a Xbox 360 and PS3 hooked up so that I can switch onto them on the 3rd monitor.
The PS3/Xbox connection works, the PC connection shows up as the monitor is detected but no display is presented (see image below problem monitor is display3, I have also tried dropping the resolution).
I did somehow get it to display a couple of times- no idea how this happened - when it did all three monitors displayed correctly.
I am now assuming that the HDMI connection needs to be active, ie a DP to HDMI active adapter between the GPU and the switch? then just go HDMI to DP on the switch?
I say this option as a HDMI to DVI active adapter is £££
SOLUTION - Ok so v odd I know but I got thinking, and after going though a bunch more alternatives (thanks to a giant box of cables) I have gone
GPU (DP->HDMI) -> 2mtr cable -> HDMI 5 port switch -> HDMI to DVI into monitor and it seems to be working
When the system sleeps I am unable to wake the monitors (they are on but blank) - this means I have to hard reset the PC and log back in, I have tried disabling hybrid sleep, PCI-E Power saving mode and still this occurs. I have tried this with only two PC's using DP (ie not the active/passive worry from above) - Any suggestions would be greatly appreciated!