Hi All !!!
Finally,got some courage ,and decided to go and register,hoping to get some answers .
So,here it goes - i've tried it with a BUNCH of different motherboards,cpus,power suplays - results are ALMOST always the same.
After a long - like more then 6 hours time with the screen turned off,the system will not respond on mouse clicks,or keyboard presses .
Finally,installed it on Gigabyte ,FM2+,A88X based motherboard,powered by 650 watt PS - 3 of 4 times it turned the screen on just fine,BUT last time - it didn't,whyyyyyyyyyyyyyyy ?!!!
The culprit is refarbrished GeForce 780 GTX,working just fine,passing all tests "with flying colors" .
What should i check - bios settings,power settings,my head ?