Don't know the model but those symptoms on many videos are commonly due to incorrect tape tension or tape path misalignment across heads.
The loading arms (the two arms which move forward pulling tape around the cylinder) either not fully loading on one or boths sides or misalignment of the guides causing tape to curl and mistracking.
Also, check short tension arm which pulls tape across the staionary audio/control head to right of cylinder. Should move freely but can stick on old dried out grease.
Also, it could be damaging your tapes. Once the tape edge is even slightly damaged it can never play back properly, even after rectifying the underlying fault. Check tape condition by lifting the cassette flap (press button on front side of cassette to release the flap).
Cobweb, June 2005
