hifi engine

AKAI GX 620 RTR

I just bought a refurbished Akai GX 620 RTR. When I connected it, I found out that the tape speed was moving too fast (sounded like chipmunks) and the speed selector which controls the speed 7-1/2 ips or 3-3/4 ips was not working at all.

Is there someone out there that can help me solve this problem? Or at least guide me to what steps I should take to solve this dilemma?

Thanks, Richard