How is the tape end detected? is it an led or a lamp? Its over 20 years since I repaired a Betamax VCR. even then I didn't see that many.
Cassette lamp failure would cause machines to cut off Leds would not fail as such but could get clouted by a cassette thereby not pointing at the end sensors or not illuminating due to broken connections.
Loading belt? sometimes would slip before loading was completed ?
May not apply to your machine but worth a quick look?
Rich.