Recently the following thing happened to my PC a couple of times:
Screen was as if covered with black and white stripes with a distinct square in the middle and the PC was not responding to input.
When the PC was rebooted it either was beeping with three long beeps or there was no beep at all.
Another weird thing was happening that may be related: from time to time when the PC was operational the buzzing continuous sound appeared on the AUX sound card output.
It also may be worth noting that both video card and sound card are integrated with motherboard.
Any ideas what could be done with that?