VCR eats tape when rewinding

A couple of possibilities: 1. Braking problems: When VCR goes from FFWD, REW, Play to stop, there are a pair of "brake pads" engaged to stop the reels, and prevent tape spillage out into the machine. These pads, often rubber like, are on levers which contact one side of each reel. If you take the cover off the VCR, and look down where the tape is loaded, you will like see these brake assemblies. If the rubber pad is missing, or lever pivot points gummied up, then this is your issue. 2. Take up reel isn't being engaged to take up the tape on tape eject. When a tape is loaded into the machine, tape is pulled from the cartridge and threaded into play ready position. When eject mode is engaged, the tape must be pulled back into the cartridge, or you will have tape hanging out the front end of the cartridge, and may get caught on the VCR internals, or at least be mangled by the cartridge door. The often issue here is likely the idler assembly pivot point is sticky. This idler pivots, moving from the take-up reel (right reel) to the supply reel reel (left one), depending on what mode is selected. FFWD & play to the right, left for REW. If this idler is gummed up at it's pivot point, movement will be sluggish at best, and might not be engaging the right reel quickly enough to pull tape in before tape eject. This idler is sitting right between the reels down where the tape sits. A little light oil on the pivot point may be enough to loosen it up. Otherwise it might need to be removed and the old grease removed, and a drop or two of light oil applied.

Quite often it is a cassette problem. The two winding reels run on plastic bases which often becomes very dry and the two reels do not run smoothly. Remove the outer casing and take the two tape reels and the tape out. Then apply a small amount of powdered graphite to the rubbing surfaces of the bottom casing. Reinstall the two reels, making sure to put the tapes in the correct positions around the tape posts, and then replace the outer casing. This often resolves the problem.