Question PC goes black screen randomly but removing gpu fixes it.

Dec 9, 2021
This issue first occurred when I set my pc to goto sleep after 15 minutes of inactivity.As expected the computer went to sleep in front of me as I was studying but the weird thing was that the computer wouldnt turn back on even if press the power button and the lights of keyboard and mouse were on. even though the screen was totally black with signal intact. I would then force shutdown it either by long pressing the power button or unplugging the power cable. I turned off the sleep setting but it would still occur sometimes randomly and after prolonged use and turning off the pc only to turn it on after sometime,It would further shorten the amount of time i could normally use the pc before it went black again, then it started to go black screen right after bios.
in attempt to fix it i have changed my motherboard, my processor , my gpu , and my psu. hence after working just fine for two days on my new gpu it has started to happen again flat out screen goes black and audio distorts then cuts completely if was playing audio.I changed the port from DVI to display port and that fixed the issue for as long as i didnt shutdowned the pc. the temperatures of both gpu and cpu never excceds 69°c.
Now if i were to remove the gpu from the pc it works absolutely fine. (the reason why i changed gpu thinking it was malfunctioning.)
my previous gpu was = sapphire r9270x
new one is = sapphire pulse rx560 4gb
motherboard = ASUS P8H61-M LE/CSM R2.0
ram= normal DDR3 8gb
psu=300 watts
cpu=intel i5-3570 3.4ghz