R9 390 refuses to work, while other GPU works on the same PC

[EmKa7a]

So, I have a XFX R9 290, I bought another GPU for cheap, Sapphire R9 390, although the sapphire doesn't work on my system, while on another PC it works fine. The 290 also works fine on both systems. I deleted the old AMD 290 Drivers, tried basically everything, but I get no screen, neither the text on the screen for no cable connection, nothing, just blank. I can hear the windows boot sound though, so the PC boots till windows with the 390, just... no screen. Even the fans don't spin. Tried the dual bios button, still nothing. The Power Supply is FSP Raider RA 750Watts. Tried on both slots of the motherboard, also with 2 different cables, one DVI and one HDMI on different screens. Same thing. Any ideas?

[i_build_nanosuits]

Use DDU to completely clean uninstall your drivers.

[EmKa7a]

2 minutes ago, i_build_nanosuits said:

Use DDU to completely clean uninstall your drivers.

Did that like 3 times

[RobTapps]

I'm having an issue close to this with a 390.. only problem is I'm on an FX CPU and can't use an onboard GPU... My PC was working fine (with the same card) then after a month of being powered off it threw a B2 code and froze on said code twice.. now no signal.. monitors switch between inputs then shuts off. If you find an issue please for the love of spaghetti post it here.