So I have an Akai CS F21 that I found at a thrift shop for $20, at the moment I have replaced the belt with a normal rubberband just to see if it works. It has soft touch controls, not the piano key and I pressed play and the mechanism tried to engage but it couldn't and only one of the plastic spindles rotated the cassette wheel which caused the tape to come out at where the head reads it. I figured out that it engages with a pair of solenoids, however, the solenoids dont appear to be engaging enough. The rubberband is a little bit loose so it isn't because it's too tight. I dont know how to continue or what I should do.
Here are photos of the solenoids, while I was assembling it back together to put it away there was a brown wire that came loose from the head. There is a photo where I circled where they were located on the deck
