One day it got jambed up and I had to wreck the tape mechanism to get it out. (long story).
This Mod will show you how to connect the lead for a 3.5 mm jack to the radio input on the circuit board.
I was not able to connect the wires successfully to the tape head input because of some humming that i couldn't get rid of. After looking on the web for the reason why there was this funny humming (too technical for me to describe. Somone else can add comments to explain) I decided to use the radio input to the circuit board. This is because the radio was not being used. The aerial was bung.
The wires from inside the adapter were pushed into the fitting on the circuit board for the radio and I could just plug the cable to the 3.5mm jack into it. This is only because I had broken the adapter and it was easy to do it this way as I was in a hurry but I could have easily cut the cable and fitted them into place. Connections for left channel , right channel and ground were marked on the board. Hot gluing those wires so they don't come out and hot gluing the plug to the circuit board and also a cable tie hold everything place.
Because it was wrecked I took the tape player mechanism out cutting the power wires. So now the selector button when moved to radio turns the sound on and sliding it back to tape turns it off. The curly wire with the 3.5mm jack just hang out the big hole where the push buttons for the tape player used to be.
These tape decks make a good sound for there size.
Later I am thinking of mounting an iPod dock on it. Have to workout how to make it charge. If someone can point me in the right direction to be able to connect a usb cable, that would be great.
Hope this helps