92 Accord LX ..radio/cassette problem

I'm still using the original oem Honda cassette/radio, probably made by Alpine. Recently the tape speed increased dramatically, .. not to the chipmunks mode, but close. Yanked unit and removed coverings for visual inspection. Found it's a gear drive, no belt design. I assume the electronic component that governs/regulates motor speed has failed. I've heard it's not a unique problem. There are repair shops that can fix it, but I'd like to do it myself, ... if possible. This radio fits my needs, and blends with the dash, so I'm not considering the aftermarket. Has anyone repaired a similar unit with the same symptom? If so, I'd surely appreciate some "pointers" and info on how to make the repairs. Thanks