Hey, I have been having this problem since past 3 days.
The display either goes black and I get the message- 'monitor going to sleep'.
Or it turns brown or white and freezes until I restart by holding down the power button.
During this the cpu lights, and all the fans are spinning.
Sometimes I get a short stuttering sound before it goes out, other time I keep getting the entire sound output without any issues but the monitor doesn't get any signal.
Even when it crashes, sometimes it reboots itself, other time I have to hold down the button.