Don't know this model. However, some very common faults with Mitsubishi VCR's of that era...
Underside of unit..capstan pulley (black pulley about the size of a pound or dime, fits onto the brass centre of capstan flywheel), splits and falls off along with the belt.
Topside of unit.. Broken teeth on main loading gear at right side of cassette loading mechanism, requires replacement and modification.
Topside of unit.. Worn reel idler, small rubber drive wheel between the reel tables. Replace or clean.
Cobweb
December 2004