To tighten the belt:
- Remove the upper two screws that hold the back cover.
- Loosen the two screws on the bottom.
- Tilt back the top of the cover, so you can access the motor mounting screws.
- Push a large screwdriver under the motor at the "S" arrow.
- Loosen screws "A" and "B", just enough to be able to push up the motor with the screwdriver.
- Push up the motor with the screwdriver so the belt gets tighter, but not very tight.
- Tighten screws "A" and "B" firmly.
- Put back the cover.