I have a DP G5, running 10.3.9, which has been working fine up to about a month ago, when it started randomly freezing (no response whatsoever). If I had music on it would go on a short stutter loop. Also, the fans come up in fighter-jet-mode and the only way out was a hard reboot. until this morning. i booted it up, it froze mid-morning, and now i can't get it to start at all. some times i get the startup chime, but not always, but I never get to any 'monitor life'. No need to mention that I have a ton of essential work file on it. suggestions?