Question No signal to monitor after switching from nvidia to amd

Jul 23, 2020
Ive tried just about everything and ive almost given up. Heres my issue:

Ive recently gotten a radeon hd7770 for a low end pc that im putting together for someone, and it refuses to give my monitor a signal. It used to have an older nvidia and worked fine before.. No windows, no bios, nada. Heres a list of things ive tried:

-popping the card into a different pc, it works fine so not a dead card?

-popping a different card into this pc, it works. Not a pcie slot issue?

-i bought a brand new corsair 450w psu. Same problem

-clearing the cmos by taking the battery out and shorting the clrtc jumpers

-taking the ram out, putting each stick into the slots one by one

-i bought a bios speaker and it gives me 1 short beep, i read that means it booted ok i think

-yes my monitor is turned on

Heres some info on the system:

Windows 10
Intel core i5 2400
Asus radeon hd7770
Asus P8H67-M LX motherboard
Corsair cv450 bronze psu