Sounds like the dreaded RSOD (reset screen of death) If you're not getting strange sound from the DC itself, it's most likely a loose or bad contact. First unplug the DC, and then open the console, remove the RF shield until you can see the power supply module on the left side. Remove the screws holding it down and pull it up. Check and clean the pins that connected the power module to the main board and maybe bend it just a bit before putting the power module back in. (bending it usually forces a tighter contact)