Optiplex 745 no signal after plugging a new video card
I have bought a Sapphire Radeon HD 5450 1GB DDR3 video card and put it into my Optiplex 745. However when I start the computer my monitor keeps flashing "no signal" error. I have already uninstalled previous Intel GMA drivers, I tried switching the video recognition from auto to onboard in bios but the problem remains. Also when I have the new card plugged in and I try connecting my vga cable to the old integrated video card I also get the "no signal" error. Maybe it's something with the psu? Anyone can help me?