PC/IBM Monitor Issue [not sure how to explain it]

Hey

Bought this PC a week ago. Everything was fine for a bit, but now the IBM keeps cutting out. It either shuts off and restarts, or it just goes black and says "no signal" before popping back on.
I already tested the IBM on my old desktop and it works perfectly fine.
There’s only one thing that might be causing this, but I’m not sure, so I'm asking here.
I had to buy this adapter https://www.amazon.com/HDMI-to-VGA-Adapter/dp/B07X8N5L7S
The IBM only has a VGA port, but my graphics card only has HDMI and DVI-D.
That's how it's hooked up, but the old PC was plugged directly into VGA.

Specs:
Gigabyte GTX 1050 2GB
AMD FX 6300
8GB DDR3 RAM
LC600H-12 Power Supply

I ran into that exact same headache myself—turned out to be nothing more than a faulty HDMI cable. I just picked up a new one, swapped it out, and boom, problem solved. Sure, there's always a chance it could be the graphics card, but honestly? I wouldn't bet on it. At least you know the IBM is fine since you tested it on another computer and it’s working perfectly without cutting out. That really narrows it down to either the HDMI or the GPU, but I'm 110% certain it's just the cable.

Larry Ortiz5 said:I ran into that exact same headache myself—turned out to be nothing more than a faulty HDMI cable. I just picked up a new one, swapped it out, and boom, problem solved. Sure, there's always a chance it could be the graphics card, but honestly? I wouldn't bet on it. At least you know the IBM is fine since you tested it on another computer and it’s working perfectly without cutting out. That really narrows it down to either the HDMI or the GPU, but I'm 110% certain it's just the cable.

I never actually said I tested the GPU on a different rig.
It runs fine without cutting out when I plug it into the TV via HDMI, so everything works there. And I didn't mention this wasn't my own PC; it belongs to a buddy. He can't test the HDMI directly, but I'm heading over there today to swap in a different GPU that has both VGA and HDMI ports. Then I'll see if the issue is the GPU slot or if it really is just the cable. Honestly, I'm leaning toward the cable too. If it were the GPU slot or something related, the audio would usually glitch out when the IBM goes dark, but the sound stays perfectly fine. My logic, anyway. Thanks.