E240: Zero position sensor for Y axes always active /
E241: Zero position sensor for Y axes never active /
E242: Unexpected activation of Y axes /
E243: Timeout of Y axes

These errors are signalling a problem on the Y axis movement.

Entering in the Y-axis service program it is possible to check the cause of
the error.

In normal conditions the display must visualize "X" instead of the
character "a".

Using the left and right arrows it is possible to rotate the arm, checking if
the status of the sensor changes accordingly.

1. If there is no variation of the above signal, if the arm does not move
or moves with difficulty or jumps.
      • Check the belt and verify that it is not broken; if the belt is loose,
          adjust its tension
       • Check cables of the Y axes motor; there can be a short circuit or
          a broken wire; check also for a loosen contact. In case of short
          circuit, replace the cable, verifying also that no damage has been
          caused to the motor driver (D27) on the CPU.

2. If there is no variation of the above signal and the arm moves, verify
the cable from the optical sensor up to the CPU board (A5). If still
there is no variation of the signals when there is an activation of the
switches, change the CPU board.

In case of no motion, it is possible that the problem is related to the
motor: in order to check this, connect the driver of the Y-axis motor to
the rotation motor, putting cable X28 into connector X26 on CPU board
(A5).