I see a lot of threads with the same issue, and I am going to post this in a few of them. I have a Sapphire Radeon RX 5700 XT. I also have an X570 motherboard (MSI MPG Gaming Edge Plus WiFi). I have a similar problem where I get random black screens. I hear sound for a few seconds and then the system reboots. It seems to happen when the computer is idle or not under a heavy load. Someone else posted a link to a video they found online with a possible solution and it worked for me. I cannot find the post or the video, though.
The problem was that the video card actually does not work well with PCI-E generation 4. (If you have a motherboard that does not have PCI-E gen 4, then this will not be your solution.)
Many (but from what I understand not all) motherboards have a setting for the PCI-E slots that allow you to select the highest generation of PCI-E that it will accept. The solution for me was to go into the motherboard's advanced BIOS settings and find the settings for the PCI-E slot where the card is plugged in. For almost everyone, it would be in PCI-E slot 1. Change the setting from Gen 4 to Gen 3. (From what I read online, we probably are not getting too much benefit from Gen 4 anyway).
I have not tested this for more than a day, but I left my computer alone for hours. It would have black-screened and rebooted after 10 minutes. So far, no black screens, no crashes, no reboots, so I think it worked.
Well, on my second day, I got 2 random black screen/reboots, so this fix turned out not to work.
I get random black screens, the sound continues for a few seconds and I get a Windows arrow, and then the system reboots. Its usually after 10 minutes to 30 minutes of the computer being idle. I have had this computer for a month and this only started happening about a week ago. I tried setting the PCI-e slot to PCI-e Gen3, I tried uninstalling last week's Windows updates. I ran a memory test. No use. The only thing the event log tells me is not helpful:
"The system has rebooted without cleanly shutting down first. This error could be caused if the system stopped responding, crashed, or lost power unexpectedly."
I have the following:
MSI MPG X570 Gaming Edge Plus WiFi
Sapphire RX 5700XT
Gskill Trident Z 3600 memory
Huh... We all have the same motherboard...
Mine does not crash THAT regularly. Mine crashes about once a week, sometimes 2 in a day though.
Always only NOT under load. No problems when gaming, ever.
I have a RTX 3080, and it's happened with a 2nd one (that's another story); I can't imagine that it WOULDNT work with the PCIe 4.0...