Mondolfo Ferro MT 2450, Техническое и сервисное руководство

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Technical service manual 23
UK
If the checks described above do not reveal any faults, replace the central unit, check-
ing for noise on the bearings if appropriate.
IT IS NOT POSSIBLE TO BALANCE THE WHEEL:
when the weights indicated by the balancing machine are applied
and then a checking wheel spin is performed, new imbalance
values appear at random.
Make the checks listed in the previous point.
Also check:
- that the geometrical dimensions set are correct;
- that the machine has not lost its calibration, by performing the three-spin calibration
procedure;
- that the cable connecting the search circuit board (encoder) to the motherboard is
connected and wired correctly;
- operation of the search circuit board (encoder) using service program “97” (see “Serv-
ice Programs). An operating defect on the search board prevents the machine from
calculating the position of the imbalances correctly. In this case, the following must
be checked:
• that the photodiodes of the search circuit board are not dirty;
• that the mechanical setting of the fork in relation to the search disc is correct.
If the anomaly persists, replace the search circuit board.
If this does not eliminate the fault either, replace the motherboard.
THE MOTOR REMAINS ON, CONTINUING TO DRIVE THE WHEEL,
and THE WHEEL SPIN IN PROGRESS DOES NOT COME TO AN END
Perform all the checks on the search circuit board listed in the previous point. Also
check that the power supply and controls circuit board is in good working order, with
special reference to the motor power supply relay.
BRAKING AT THE END OF THE CYCLE IS TOO LONG OR TOO NOISY
- Check the brake shoes for wear and replace them if necessary.
- Clean the working surfaces.
THE WHEEL SPIN DEVICE IS NOISY
Check, in this order:
- that the roller is not worn;
- that the brake shoes are not worn;
- that there is no mechanical damage to the motor;
- that the wheel spin device is set correctly;