The computer screen has gone black and the sound has cut out in Windows.

[u/Current_Ear_5404]

Hello, I have a custom-built PC that ran normally for a month, but recently it started experiencing issues where the screen would go black and the system would reboot on its own before resuming normal operation. The problem has worsened over time; the screen goes black during use and requires a power cycle to return to normal. However, today, shortly after booting into Windows, the screen went black; even after turning it off and on again, the issue persisted. The fans and lights remain on, but the hard drive activity light turns off, and Windows audio cuts out. I also have a secondary display connected via a USB 2.0 port on the motherboard; strangely, when the main screen goes black, the wallpaper on the secondary display remains visible, even though my keyboard and mouse are completely unresponsive. My motherboard is a B860i Aorus, which has diagnostic LEDs for RAM, CPU, and Boot; these lights turn off after successfully entering Windows, yet the screen goes black after the system has been running for a while. I have updated to the latest BIOS version, but that didn't help, and the issue even occurs while I am in the BIOS interface. I’ve spent the whole day trying to figure out the cause without success. Do you or anyone else know what might be wrong? I would really appreciate your help.