Hi all tech-heads. I have a question. I have a Sony wm-4 tape walkman but the fast forward, rewind dont work. I dont use these functions but still would like to find out why. I read on this forum that there is a small plastic part on either the wm-1, wm-4 or wm-f1 that breaks. Does anyone know if this part is the cause for the fast forward, rewind function not working or is there another problem? Hope to hear from some experts.