[Coco] Joystick fire button not working-Repair?

[rjlilko at randing.ca]

The joystick interface on my CoCo1 has partially stopped working. The
joystick properly moves the cursor but the fire button does not respond.
This happens on both left and right. I checked the joysticks out on my CoCo
so I know they work. Before I begin disaasembly of my CoCo1, has this
happened to anyone else? Specifically the joystick interfaces (L&R) not
responding to the button press.

 

Thanks for any assistance/comments.

 

Arjay