Drop a core, add a cannon comp and link a cannon module to it. Add an activation module. Check that cannon comp is visible in the weapon menu.
Link activation module to cannon comp. Check that cannon comp is no longer visible on menu.
Unlink activation module from cannon comp.# put cannon computer with a linked module on your ship
# connect a button to the computer
# disconnect the button from the computer
-> shipcore + cannon computer link is not automatically restored, Check that cannon comptherefore it also does not re-n't appear in the weapon menu again.