BlackScreen on Ex58 ud3r

Mainboard:Ex 58 ud3r with last Version of Bios.
Cpu:i7 920
Ram:Kingston hyperx 2x2gb 2000mhz.
Video:asus hd 5770 1gb 128 bits
Power supply:rasrurbo 650w
My problem is:after hours and hours of hard wire management my screen goes black.i will explain my problem in detail:after aff of that i turn on my pc and everything works fine.I had play for several hours and i look inside my case and i observed that one cooler wire was not in good position(what i mean is that it look messy in the case) and i decided to change it position.Without to touch anything except the place of the cooler conection i turn on my pc and surprise:black screen!
My bios post i heard the beep.It enter in windows because the log on sound is audible.
What i done:
change the gpu place in the other pciexpress slot:same
batery remove same
clear cmos jumper same
boot without hard drive and dvdrw same
change the wires and connection same
remove the cpu,place it back with all conection same
remove the ram,beep.Remove one same thing
remove the gpu beep
change with another gpu,same
I had try the gpu in another pc and it's work.
When i did all of that i was sure that everything was in it's place.
When i mean same,i mean that the computer boot,the bios beep that everythig works it's present and it enter in windows7.
One more thing:i wasn't use overclock and i had tested with another monitor,same thing
So,any ideas?
when i did all of

Did you put the GPU back into the original PCI-e slot??

Maybe you have a PSU problem?? What is the make and model of PSU that you have?? Please include a link, if at all possible.

I had a Rasurbo Power gamer GAP656 650w.
I had try another pci express conector and the conector that came with the gpu in the box.same problem

I don't have another PCU.Everything work just fine,no bluescreen or restart until I did wire management.I am sure that I did everything fine.The problem had shown after I change the cooler conecion(120 mm case fan)

Is there a possibility to get it working?
And I don't understand why has to malfunction like that,i mean it broke so easyly

You could take out everything out of the case and lay it flat on a non-conductive surface (cardboard works well). Than try and power up the system. Maybe you had a loose screw or something that shorted out a circuit on the mobo somewhere.