Info Powered on PC without unplugging GPU while out of socket, burned something

[Wd2019]

I was messing around with a PC that wouldn’t power on whatsoever when the GPU was plugged into both the motherboard and the PSU. Specifics aren’t important here when I get to my main question. I was taking it in and out and noticed that it even powered on while the PSU wasn’t connected. However, I accidentally left it plugged into the PSU the last time I powered on the PC, and the GPU wasn’t in the PCI express socket... something made a popping noise and I smelled a burning smell. The PC no longer worked. I’ve disassembled it for sale now anyway, but I’m wondering if the burning smell came from the MOBO or the PSU? Which one is likely blown? The MOBO looks fine, nothing burned. The PSU, however, doesn’t smell burned, and looks flawless as well. Anyone know what my action caused and which one likely just blew up?

 

[DSzymborski]

Let's start with the full complete specs and the entire tale. You've started with the PC not powering on; I'd like to know the circumstances of what happened leading up to it not powering on.

 

[Wd2019]

Let's start with the full complete specs and the entire tale. You've started with the PC not powering on; I'd like to know the circumstances of what happened leading up to it not powering on.

It was a A-320M-S2H MOBO and a couple cards we tried. First, a GTX 555. The PC wouldn’t power on when the card was plugged in. We made sure EVERYTHING was secure and clean. So, we assumed the GPU was dead. We bought a GTX 650 off Newegg and tried that - same result. The PC worked 100% without the GPU in, but somepletely refused to respond to the power button whatsoever when the GPU was installed. However, I did manage to get a response from the PC when I plugged in the GPU alone into the MOBO without the power cable from the PSU. It powered on. But indicator lights on the GPU showed it was getting power from the PSU cord when it was plugged in, and the PSU was brand new, as was the cord, so I ruled that out as the issue. Right as I was about to give up and just get someone who knows computers better than me to handle it, I made the mistake of leaving the PSU cable attached to the GPU while it was disconnected from the MOBO. When I pressed the power button I immediately realized I had forgotten to unplug it. It made a popping sound and smelled like burned rubber for just a short moment. So, in summary, I burned something, but Idk what🤷🏻‍♂️

 

[DSzymborski]

It was a A-320M-S2H MOBO and a couple cards we tried. First, a GTX 555. The PC wouldn’t power on when the card was plugged in. We made sure EVERYTHING was secure and clean. So, we assumed the GPU was dead. We bought a GTX 650 off Newegg and tried that - same result. The PC worked 100% without the GPU in, but somepletely refused to respond to the power button whatsoever when the GPU was installed. However, I did manage to get a response from the PC when I plugged in the GPU alone into the MOBO without the power cable from the PSU. It powered on. But indicator lights on the GPU showed it was getting power from the PSU cord when it was plugged in, and the PSU was brand new, as was the cord, so I ruled that out as the issue. Right as I was about to give up and just get someone who knows computers better than me to handle it, I made the mistake of leaving the PSU cable attached to the GPU while it was disconnected from the MOBO. When I pressed the power button I immediately realized I had forgotten to unplug it. It made a popping sound and smelled like burned rubber for just a short moment. So, in summary, I burned something, but Idk what🤷🏻‍♂️

OK, now all the specs?

 

[Wd2019]

OK, now all the specs?

Don’t see why it matters that much, but it was 16GB of DDR4 2400mhz 288-pin RAM (don’t remember the brand), a Corsair CX 650M PSU, a WD Blue 1TB HDD, a Ryzen 3 2200G APU, the MOBO listed above^, the ASUS GTX 650 GPU, and Windows 10 as the OS