Question Gigabyte rx460 (4gb) rev. 1 not recognized by my computer

[elkym]

OS: Lubuntu 19.04
(probably not relevant-- this was happening when I had no OS on the system, or when I ran LinuxMint)

Motherboard: Gigabyte 78lmt-usb3 rev. 5.0 (has onboard graphics)
CPU: AMD Phenom FX 4100 (3.6 Ghz quadcore)

[ I used to use the onboard video, later I upgraded with a Gigabyte GV-N210SL-1GI (rev. 1.0) ]

GFX card I'd like to upgrade with: Gigabyte rx460 (4gb) rev 1.0 [rx460wf20C-4GD]
From what I can tell, the card isn't dead (it came from my brother).

When this card isn't in use, the onboard video works fine with 3 different cables (1 hdmi, 2 individual dvi cables).

The fans on the GFX card kick on shortly after powerup, but I get no output from the card.
I'm still trying to get the onboard graphics to run while the card is in, so I can get the machine booted up and then try and see what the machine is actually seeing at the PCI connection.

I'm new to some of this, but I've been tinkering for quite a while-- and I'm kinda stumped.

PC Partpicker says my setup is compatible, and the MB and GFX are even the same brand, but no luck so far.

Any ideas?

 

[Phillip Corcoran]

PSU make & model?

 

[elkym]

CORSAIR CX-M Series CX450M 450W 80 PLUS BRONZE

 

[elkym]

It appears I have successfully booted into lubuntu, while forcing the system to ignore the new graphics card. This is progress.

I did this by blacklisting the amdgpu driver in grub.

Unfortunately, while I have more control over the system because I learned a bit about this, I am unable to figure out how to do the reverse, and tell the radeon driver to hand over graphics control to amdgpu.

I would think that if I force a disable to the IG (radeon) driver, that I'll just end up with no video output.

I'm learning bits and pieces about user-mode-setting versus kernel-mode setting, and it seems that somehow this is the crux of why I'm throwing the errors and not getting video.