Probably solenoid that releases the brake and allows the gearbox to spin. I suspect water seal at base of drum leaked and sprayed water over solenoid causing it to burn out or otherwise fail.
Best option is probably to get a spare machine for parts (Refuse Transfer Station, i.e. the tip, almost free) and take it apart, figuring out how it works. These machines are now about 20 years old. Your would be better off to 'upgrade' to a SmartDrive of some type. The design and engineering is totally different - in a different league. Even if you bought brand-new at $600, that's hardly a waste of money considering that it will outlive the 380 in some ways and do a better job as well (though repairs at the ten-year mark get expensive). The SmartDrive has no gearbox, belt, clutch, brake, or solenoid - a lot less to go wrong. Good luck with whateve you do -Alex
Alex Shepherd, January 2008