I was removing my motherboard so i had to remove all the cables sata, power supply etc. When i was finished i put all the cables back in place but when i try to boot up the os (windows 7), it got stuck to flickering symbol or underscore "_" on black screen for so many times. To solve this issue by repairing windows, i install windows7 boot file to usb. But when it displays "press any key to booy from USB", i pressed but nothing happens. The whole system restarts and i cannot get pass that message. Please help