New RX480, erratic startup behavior

darkspartenwarrior

Honorable
Jan 15, 2013
323
0
10,810
Build:
i7-3930k
16GB Corsair 8x2 1600MHz RAM
Intel DX79SI
Radeon 7950(previous card), trying to replace it with an RX480
Corsair TX750
180GB Intel 520 SSD
1TB Seagate Barracuda
Problem: After uninstalling 7950 drivers, taking out the card, and putting the RX480 in(And plugging in power/ensuring it was seated/screwing in the back), it displays random colors upon boot(colored square in the middle, scattered lines of colors on the outside). However, once it gets to the splash screen, the graphical errors stop and it displays the BIOS normally, after the BIOS ends, it displays the BIOS splash again, except with the previous graphical glitches, and eventually displays a black screen with the code 0_ in the bottom right corner.
This build is just under 4 years old and the only modification I've made is adding 8GB of RAM very recently, with no hiccups. Additionally, after reinserting the 7950, everything works fine, I think at this point its either a bad GPU(It displays the BIOS fine, so I doubt it), or motherboard incompatibility(It is a 4-5+ year old design).

Also, the mobo does post to 00(successful post), it just wont boot the OS
 
Solution
I'd go with your initial "bad GPU" diagnostic.

When the GPU boots, it is in dumb VGA adapter ("frame buffer") mode where the CPU draws directly to GPU memory and all the GPU does is refresh the display. It is entirely possible that there is a fatal flaw which does not get triggered until the OS begins loading GPU drivers.

... or what greens posted while I was writing. Updating the BIOS while hitting a brick wall for no apparent reason usually doesn't hurt.

InvalidError

Titan
Moderator
I'd go with your initial "bad GPU" diagnostic.

When the GPU boots, it is in dumb VGA adapter ("frame buffer") mode where the CPU draws directly to GPU memory and all the GPU does is refresh the display. It is entirely possible that there is a fatal flaw which does not get triggered until the OS begins loading GPU drivers.

... or what greens posted while I was writing. Updating the BIOS while hitting a brick wall for no apparent reason usually doesn't hurt.
 
Solution

darkspartenwarrior

Honorable
Jan 15, 2013
323
0
10,810


I thought that as well except the BIOS splash screen and the BIOS itself(settings) display perfectly fine, with only the screens before that and after it being glitched out, also when I first installed the card there weren't any drivers, I uninstalled them before the card upgrade. I updated the BIOS to the most recent one after reinserting my 7950 and I'll see if it now works.
 

InvalidError

Titan
Moderator
If you have no GPU-specific drivers installed, Windows will use the "default VGA adapter" drivers - can't boot the UI without GPU drivers of some sort, which means that the GPU still gets re-initialized under non-BIOS/UEFI control and completely different operating parameters.