Then the next take, I discovered (to my horror

THEN, I switched to another tape. It was also recorded at 15 ips, but I thought, okay, it worked before. I turned it on and let it rip, then went off and practiced some piano. Came back when the tape suddenly stopped. Listened to the transcription, and, oh, no! It was acting like it had been recorded on one of those cheapo machines without a capstan. It sped up, it slowed down, it sped back up...it slowed WAY down. It stopped. My DAW (ancient though it is) is good, but it's not THAT good.
Any suggestions on how I can fix the tape deck? I don't expect anyone in this area has ever worked on one before. My dad could have fixed it, and so could his best friend, but they're both gone now. I'm thinking maybe open it up and oil some parts?
Help!
Thanks!
Merry