I have a AMD phenom II 945 processor,ASUS M4A88T-M motherboard,4x2 XMS 1600 DDR3 corsair RAM,500 GB SATA and another 160GB PATA Seagate Hard Disk,a Local but good quality PSU.
I have been having this problem from over 6 months now,My PC works fine for sometimes ,but it randomly freezes with a completely garbled screen (and at times restarts after showing the garbled screen).If any song or audio was playing then it starts looping with screen garbled.I have noticed that the HD LED gets completely turned off when the PC freezes and stays off until it is manually restarted.
I have got a replacement for the motherboard,changed my RAM stick,Changed My PSU and even got the Processor replaced from AMD,but still the problem persists.
I am wary of HArd disk problem because i checked it the seagate tool,and there was no problems found,i even used only the SATA and only the PATA (one at a time) but still the problem persists.
All the drivers are up to date,and the problem occurs both in xp and in windows 7.So it cannot be an OS related issue,and i have even low level formatted my hard disk which eliminates the virus possibility.I have checked the temperature and it is well below 45 degrees(so its not overheating problem)