HELP! New Build lost display after 'force' off....HELP

Hi everyone,

Ok, I'm totally stumped now...

Just built my new desktop and I was at the point of installing the OS, when I got the "DVD driver missing" error and I tried to shut down.....didn't work, so I swtiched it off at the PSU.

Since then, I cannot get the desktop to display again!! (turns on, but no display)

There is no onboard graphics, so I have to rely on the GPU....connected to a 22" Samsung monitor via DVI.

Breadboarded, and same situation. In addition, I couldn't turn it off (via screwdriver) and again had to turn the PSU off.

Athlon X4 860k
Gigabyte GA-F2A88XN-WIFI Mobo
16GB RipjawsX
HIS Radeon R9 280 IceQ OC 3GB
Case, Thermaltake Core V21
750 Corsair modular PSU

Any thoughts????

One point, the risers are bent in the case itself, so there are no "standoffs" installed.

I don't want to reset CMOS, as I understand this would revert the BIOS back to original. I can't do that as without the flashed BIOS (I got at Memory Express), the Mobo won't support my CPU.

I'm so confused. I would understand if nothing had displayed initially, but to get as far as ready to install the OS for an issue to arrise, I'm at a total loss.

I'd appreciate any help/suggestions.
check that the rear io shield metal not faling into the usb or ethernet ports. make sure it not shorting anything on the bottom of the mb. if the case mb tray is not flat but raised..the weight of the gpu may be making the mb short out to the bottom of the tray. check all your cables for a cut and or short. look at the front case panel make sure the wires are on tight and nut cut or shorted.
Also, there's now no way to turn it off unless I use the PSU switch. I connected all the control connectors from the case, and holding the power button down does not work (nor does the reset button).

Reading elsewhere seems to read that the CPU cannot execute the BIOS? Which is potentially the case as the Mobo doesn't support the CPU within an updated BIOS....I'm getting concerned something needs to be returned...
take the mb out of the case and with just one ram stick and the gpu and power supply on top of the mb box see if the mb will post. you have to use a small screw driver to short the power switch on pins. also do as other have posted check with the green wire to black wire on the 24 pin atx plug on the power supply see if the fan turns on. if not the unit is dead.
Update: The same components that work out of the case, will no longer post & display IN the case (I moved everything I tested with outside, back in & nothing).

In addition, when it was out, the power button (the only connector I attached) would turn on & off. Now it's back inside the case, it won't turn off via the button, only on.

The plot thickens apparently....
Further update. Something is shorting from the case. I sat the MB on the 'risers' (no standoffs in this case - they're pressed from the case itself) with no backplate, attached the GPU and bingo! Display.

I screwed everything down, without the backplate being in place (figured, if this was the cause, so be it! I didn't need a backplate) but back to no display.

I thought perhaps I was using the wrong screws to secure the MB down.....try the smallest I could find (1mm shorter than the ones I was using) but still nothing.

I'm totally at a loss, other than the fact it's related to the case.....