reel tilt

[Mkd3b]

s2000 would get an occasional reel tilt where the reels would turn slowly open door turn key close door would be fine for a bit
Now getting reel tilt #4 on a 5 reel machine Key does nothing but go to accounting have checked connections and reseated harness.
also optics seem to be ok as when lift door handle and reseat acting normal.  also the error definitely  follows the reel position and when open and close the door the reel in question only advances one symbol and stops
so question is what fails on a particular reel generally not much there other than motor and optic

[lookes]

Check the connector on the reel tray at position 4 to see if it has pushed back, or pins are pushed back.
The MPU is not seeing the reel move. If it doesn't, it stops trying. That is why it moves a bit and stops.
Not an uncommon problem.

[Mkd3b]

Problem has progressed to machine not booting up and red lights flashing on MPU
Not a good sign at all