Question Bad GPU or PSU? No boot problem RX 580

[Heavy_Artillery]

Hi, yesterday I left my PC on and came back to my monitor off, so I touched the keyboard thinking it was the usual power saving feature, only to find that the system wasn't giving out a signal and the keyboard + mouse were completely off while all the fans were still spinning. Tried to reboot, the PC turned on with the usual POST beep but once again no signal and no lights on kbm. The monitor and cable are fine. Also tried removing the cmos battery, reseating the RAM, reseating the CPU, booting with RAM and CPU only with a VGA connection, still nothing, however I noticed that when turning it on after removing the GPU, the keyboard and mouse receive power from the motherboard. It's ONLY when the GPU is connected that the peripherals don't get power.

After countless times of retrying I took out the PSU and connected it to an old system (Dell XPS 420) and it booted just fine. I then took out the GPU from the 420 (ATI Radeon 3870) and connected it to this system, and it also finally booted. So my question: is the PSU failing or is my GPU dead? Or could it be a motherboard problem? The build was running just fine for 4 years prior to this.

Specs:
Windows 11 Pro 23H2
CPU: AMD Ryzen 5 2600
GPU: Sapphire RX 580 8GB
PSU: EVGA 500 BR
Motherboard: ASUS Prime B450m-k
RAM: Corsair Vengeance 16GB 3000

 

[RealBeast]

Did you try the RX580 in the Dell XPS 420?

 

[Heavy_Artillery]

Did you try the RX580 in the Dell XPS 420?

Yep I just tried this and got a black screen, so it's most likely the rx580, but why would it randomly fail like this? Also it doesn't explain why the b450m-k wouldn't display a signal through VGA...

 

[RealBeast]

Yep I just tried this and got a black screen, so it's most likely the rx580, but why would it randomly fail like this? Also it doesn't explain why the b450m-k wouldn't display a signal through VGA...

Yup, more likely the RX580.
What CPU do you have in the B450M-K, and does it have integrated graphics in the CPU? (I'll give you a hint: AMD Ryzen 5 2600 does not have integrated graphics). Both the board and the CPU must support integrated graphics to work.

 

[Heavy_Artillery]

Yup, more likely the RX580.
What CPU do you have in the B450M-K, and does it have integrated graphics in the CPU? (I'll give you a hint: AMD Ryzen 5 2600 does not have integrated graphics). Both the board and the CPU must support integrated graphics to work.

Oh wow I didn't know this haha. Thanks for the hint 😅 Looks like I'm due for an upgrade anyway, but it's a shame since I think the rx580 was still a pretty capable GPU.

 

[RealBeast]

Oh wow I didn't know this haha. Thanks for the hint 😅 Looks like I'm due for an upgrade anyway, but it's a shame since I think the rx580 was still a pretty capable GPU.

Yeah, I tend to lose the better GPUs, I still have a drawer full of GT220.