So today at the pc repair shop my hdd was changed and also the bios of motherboard was reflashes because the older one was corrupted (also the previous hdd was broken)
I witnessed my pc working after installing windows 7 and then i came home and plugged the pc. And it doesn't turn on , no lights at motherboard or gpu , no sound.
My power supply is 6months old ocz 650w.
What could have changed in an hour between the store and coming home? I checked the cables and they are not loose.