Mondolfo Ferro MT 2450 Operating manual

MT 2450
Code 4-131046_uk - 12/2013
Technical service manual

2 Technical service manual
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Technical service manual 3
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INDEX
ELECTRICAL HOOK-UP................................................................................. 4
SERVICE PROGRAMS .................................................................................... 4
POWER SUPPLY BOARD SWITCH AND PEAC COMMAND SETUP .......... 8
E2PROM (t4) MEMORY ZERO-SETTING PROGRAMME ........................... 8
UPDATING THE CONTROL UNIT OF THE MBE BOARD........................... 9
DOWNLOADING THE SOFTWARE AND FIRMWARE FROM THE
INTERNET FOR CARD UPDATING............................................................... 9
UPDATING THE FIRMWARE FOR THE MBE161 CARD............................ 10
INSIDE SENSOR........................................................................................... 12
REPLACING AND ADJUSTING THE PICK UPS.......................................... 16
REPLACING THE CENTRAL UNIT.............................................................. 16
ADJUSTING THE WHEEL SPIN DEVICE.................................................... 17
REPLACING THE WHEEL SPIN MOTOR AND/OR ROLLER.................... 18
REPLACING THE BRAKE SHOES............................................................... 19
TROUBLESHOOTING .................................................................................. 20
Code 4-131046_uk - 12/2013

4 Technical service manual
ELECTRICAL HOOK-UP
The balancing machine operates on single-phase power and is supplied preset for the
specified power supply (115 VAC or 230 VAC).
WARNING
The power supply cannot be modified because the motor is specifically designed for
the mains voltage and frequency specified on purchase.
SERVICE PROGRAMS
These programs are designed to make available a number of data allowing the effi-
ciency of various parts of the machine to be checked quickly and easily.
The selection is made as follows:
- press either of the two arrow keys and then, within two seconds, the key for setting
the wheel dimensions. This preselects the first service program (87);
- press the arrow keys to preset the subsequent (or previous) programs available, until
the program of choice is located. When each preselection is made the code 8X ..9X
(with the X varying depending on the program) appears on the left-hand display, and
the message “Ent” flashes on the right-hand display to indicate that “Enter” must be
pressed to confirm the selection made.
- press the “Enter” key to confirm.
If the preselection is not confirmed within about three seconds, the system exits from
the Service environment automatically.
The service programs which can be selected by varying “X” are described below.
87 Working Environments
- allows three different operators to use the machine simultaneously:
Selecting the program displays:
- the message 1, 2 or 3 on the right-hand display;
- the message OP (operator) on the left-hand display.
This service program allows the operator (1, 2 or 3) to be selected by pressing the “En-
ter” key.
To confirm selection of a different operator, press the F key.
The following are retained in the memory for each working environment:
- balancing modes;
- working environment
- wheel dimensions;
- the last passage of the optimisation procedure (OPT).
To exit from the program (and the Service environment) press the “F” key.
90 Automatic Position Search (RPA):
Selecting the program displays:
- the message RPA on the left-hand display.

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- the message ON or OFF on the right-hand display;
The automatic position search function can be set ON or OFF by pressing the “Enter”
key.
To exit from the program (and the Service environment) press the “F” key.
91 Thresholds and rounding-offs
Remove/restore:
- the visualisation of the first gram of unbalance;
- rounding-off to the nearest inch for the diameter measured with the automatic
sensor.
The selection of the programme determines the visualisation:
- of the “1 oF” message on the right display;
- of the “on .5” message on the left display.
During normal operation, also when the “gr x 1” unbalance visualisation mode is
selected, the first gram of unbalance is not shown. In this condition, the message “1
oF” appears on the right display when programme “91” is selected. When the ENTER
key is pressed, the first gram is then displayed and it is possible to amplify machine
sensibility (the message “1 on” appears on the right display). By pressing the ENTER
key again, you can set the two modes alternatively.
When the machine is turned on, it prepares to display the diameters measured with
the automatic sensor, rounding-off to the nearest inch. In this condition, the messa-
ge “on .5” appears on the left display when programme “91” is selected. When the
ENTER key is pressed, the diameter measured with the automatic sensor is then
displayed with the precision of a tenth of an inch (the message “oF .5” appears on the
left display). By pressing the ENTER key again, you can set the two modes alternati-
vely.
Important
Pressing the ENTER key changes the setting shown on the display, in corresponden-
ce of which the central part of the centred position indicator lights up. To transfer the
control from one display to the other, press either of the two arrow keys.
You can exit the programme (and the service environment) by pressing the “F” key.
The programme is used to
- display the unbalance values with the maximum precision allowed, so you can balan-
ce a wheel perfectly and then carry out further checks on it;
- display with the maximum precision allowed (tenth of an inch) the correspondence
between the diameter values measured with the automatic sensor and the nominal
wheel values.
93 Display of software release installed
Selecting the program displays:
- the message “rEL” (release) on the left-hand display.
- the numerical message “XX.Y” on the right-hand display, corresponding to the re-
lease of the program installed (also stated on the eprom label).
The “Enter” key can be pressed to display the date of the release in the format: day,
month, year.
To exit from the program (and the Service environment) press the “F” key.

6 Technical service manual
The program is used to:
check the release of the program installed on a machine to allow updates to be carried
out if necessary without having to remove the circuit board from the machine to read
the eprom label.
94 Standard imbalance values display
Selecting this program displays the imbalance values for the last wheel spin per-
formed, calculated with reference to the standard calibration coefficients (the ones
used by the machine when the circuit board has never been calibrated or if the cali-
bration coefficients calculated previously have been accidentally deleted).
To exit from the program (and the Service environment) press the “F” key.
The program is used to:
- optimise the clamping of the pick ups on the basis of the mechanical characteristics
of the central unit and those of the specific electronic circuit board.
95 Display of first gain synchronisation calibration coefficient.
Selecting the program displays:
- the string “F” on the left-hand display
- the synchronisation calibration coefficient on the right-hand display.
The value is expressed in notches (whole part) and eighths of a notch (decimal part) of
an encoder (one notch corresponds to about 1.4 degrees).
To exit from the program (and the Service environment) press the “F” key.
The program is used to:
- check that the values of the synchronisation calibration coefficient displayed are
within the permitted range, which is from -2.0 to +2.0.
96 Display of pick up signals and relative synchronisation
Selecting this program displays:
- the message “96” on the left-hand display;
- the message “GO” flashing on the right-hand display;
Before selecting the program the operator must:
- set CAR environment;
- fit an average-size 4WD wheel (generally 6” x 15”) on the wheel balancer;
- balance it precisely after setting “1 on” mode using service program 91;
- apply a weight of 100 gr (3.5 oz) to the outside of the rim;
- perform a wheel spin.
The machine acquires the imbalance signals and then displays in this order:
- the difference F between the signals of the pick ups and the ideal value of 180° (on
the right-hand display). The value is expressed in notches (whole part) and eighths of
a notch (decimal part) of an encoder (one notch corresponds to about 1.4 degrees).
- values proportional to the level of the signals received from the Inside and Outside
pick ups.
Notes
- The values displayed do not depend on the dimensions set.
- With the wheel at a standstill, the data read can be displayed in alternation by press-
ing the “Enter” key.

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- A series of wheel spins can be carried out without exiting from the program.
- To exit from the program (and the Service environment) press the “F” key.
The program is used to:
- check that the values displayed are within the permitted ranges, as follows:
•synchronisationdifference F from -2.0 to +2.0
•internalpickupsignal  I from 200 to 280
•external“ “  E from 110 to 170
97 F Displaying search circuit board functions (encoder)
Selecting the program displays:
- the message “Pos” on the left-hand display.
- a numerical value between 0 and 255 on the right-hand display as the angle of the
shaft varies.
If the program is recalled immediately after the machine is switched on, the display
shows the message “Pos rot” to indicate that the shaft has to be turned until the en-
coder zero mark has passed in front of the search circuit board: at this point the mes-
sage disappears.
It is also possible to perform a wheel spin (the message “97 GO” appears on the dis-
play) during which the pulses counted by the search board are read. At the end of the
wheel spin the left-hand display shows the expected count value (256) while the value
actually counted flashes on the right-hand display. These values are displayed for
about five seconds, after which the shaft’s current angle appears.
To exit from the program (and the Service environment) press the “F” key.
The program is used to:
- check the efficiency of the search circuit board. When the shaft is turned in either di-
rection, the count must change continuously from 0 to 255, and at the end of a wheel
spin the two values displayed must be the same.
98 Visualisation of internal sensor functions
The selection of the programme determines the visualisation:
- of the “di” message on the left display;
- of the value in notches deriving from the diameter sensor on the right display.
Moving the lever of the sensor, the value is continuously updated.
Pressing the key to set the keypad wheel data, you will see:
- the message “d” on the left display;
- the value in notches deriving from the distance sensor (1 notch = 0.5mm).
This value is updated by moving the sensor “in - out”.
Pressing the key to set the keypad wheel data, you will see:
- the message “FC” on the left display;
- the message “0-0” on the right display that indicates the status of the zero sensors
used for the zero-setting of the automatic sensor.
Specifically, the message on the left hand side is relative to the distance zero posi-
tion sensor, while the message on the right is relative to the diameter zero position
microswitch.
This message changes to “1-1” when the internal sensor is extracted and returns to
“0-0” when it returns to the rest position. If this update does not occur, carry out the

8 Technical service manual
checks as described in the “internal sensor” chapter.
- You can exit the programme (and the service environment) by pressing the “F” key.
The programme is used to
check the efficiency of the sensors used for automatic data input. Moving the sensor, the
values displayed must vary continuously within the following intervals:
diameter sensor ......... see chapter “internal sensor” paragraph “diameter sensor”
distance sensor .....................from 0 to 750
POWER SUPPLY BOARD SWITCH AND
PEAC COMMAND SETUP
The complete table is provided to allow any checks required.
MBE 161
SW1-1
SW1-2
SW2-1
AVAILABLE NOT MANAGED
SW2-2 Test/Work OFF
SW3 START/STOP
inversion I
JINT1 Set on
“EM8xxx”
Jumper for analogue selection of
groups EM7xxx or EM8x
JEXT1 Set on
“EM8xxx”
Jumper for analogue selection of
groups EM7xxx or EM8x
E2PROM (t4) MEMORY ZERO-SETTING
PROGRAMME
Proceed as follows to perform the E2PROM calibration parameter zero-setting test t4:
- With the machine switched off set the dip-switch (C, figure 1) that is necessary for
accessing the diagnostics mode, i.e.:
MBE161: SW2 DSW2 in ON;
- Turn the wheel balancer on;
- Use the arrow keys to select the test until the following appears on the display:
“t 4” on the right display
- Press the enter button to confirm the selection. The card will automatically reset the
calibration parameters;
- When the operation is complete the following will appear on the display:
ttt on the left display;
ttt on the right display;
if “test” correct, whereas “Err 5” if there is an error during the test. Pressing the F key
exits from t4 and ttt – ttt appears on the display.

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Perform the t4 test again in the case of an error. If the outcome is still negative, replace
the MBE161 card.
- Turn off the machine and return the dipswitch to its original position (all switches are
OFF).
Fig.1
UPDATING THE CONTROL UNIT OF THE
MBE BOARD
These cards are used with wheel balancers with gear transmissions or with a rubber
wheel.
Board description
- MBE161 card. Processing board and interface with completely LED-based display.
The board is controlled by a microprocessor with relative firmware.
- The MBE161 card firmware version can be identified in the SERVICE environment
under CPU.
DOWNLOADING THE SOFTWARE AND
FIRMWARE FROM THE INTERNET FOR
CARD UPDATING
If one or more cards needs to be updated, the FIRMWARE that is required can be
downloaded from the internet.
To download the updated firmware and graphics versions from the internet, pro-
ceed as follows:
- Connect to the manufacturer’s WEBSITE

10 Technical service manual
- Select “Private area”
- Enter your username, password and select “Enter”
- Select “Software Updates” in the new screen.
- In the “Keyword” field, enter the keyword that corresponds to what you want to
download. For example:
- If you want to download the programming software (SAB16X or SAB32F) for the
update via PC enter “SAB”.
- If you want to download the MBU, MBE or SEB FIRMWARE enter the name of the
machine to be updated.
N.B. The downloaded files are in a compressed format (.zip) and must therefore be
unzipped before they can be used.
UPDATING THE FIRMWARE FOR THE
MBE161 CARD
To update the firmware, the SAB16X programme is necessary. If it is not already instal-
led on the PC to be used for the update, it can be downloaded beforehand as explai-
ned in the previous paragraph. Then launch the “setup.exe” programme to install the
programme.
Important: the SAB16X programme is only compatible with Windows operating
systems 98SE, 2000 and XP Professional.
- With the machine switched off set the deep-switch (A, fig. 2) which is necessary for
the programming based on the card to be updated:
- MBE161: SW1 DSW2 in ON;
Fig. 2
- Connect one end of the serial cable code 8-21100224 to the “JPS1A” connector of the
card (B, fig. 2) and the other end to the RS232 serial port of the PC. If the PC does not

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have a RS232 port use the USB/RS232 adapter code 8-21100226.
- Turn the wheel balancer on.
- Open the previously downloaded file with the .”bin” extension of the firmware
version to be updated. The control window for the SAB16X programme will open
automatically.
- Select the COM serial port where the programming cable is connected to the PC.
- Select the Start key to start the programming.
- The programme starts by deleting the software version on the card to be updated,
displaying the following image on the status bar.
- When the “Programming” box opens, the “OK 100%” message means that the pro-
gramming was completed successfully.
- At the end of programming, close the programme, turn off the machine and return the
deep switch to its original position (all switches are OFF).
- If an error message is displayed, check the serial cable wiring harness and repeat the
programming procedure, turning the machine off and then on.

12 Technical service manual
INTERNAL SENSOR
Select Function 98 to display the sensor signals
Diameter sensor [di]
Fig.2a
Check that the machine reads the number of notches indicated below in the following
positions:
Position 1 with lever fully forwards, 0
notches
Position 2 with lever fully backwards, 666
notches (maximum permissible error +/- 5
notches in indicated position)

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Check the following if the sensor (A, Fig. 2a) does not read:
- the connection flat;
- that the sensor is correctly assembled in its housing.
If these checks do not rectify the problem, replace the sensor (A, fig.2a) as follows:
- remove the weight tray
- remove the sensor lever;
- disconnect the Picoflex from the sensor;
- remove the sensor A, undoing the two fastener screws (B, fig.2a);
- replace the sensor, assembling it by following the disassembly directions in the
reverse order;
- check the sensor reads correctly, as indicated above.
Distance sensor [d]
Fig.2b
Check that the total travel is 750 notches (maximum permissible error +/- 5 notches
along entire travel);
Check the following if the sensor (C, Fig. 2b) does not read:
- the connection flat;
- the correct mounting of the sensor in its housing (Picoflex connector in the direction
of the swinging unit);
If the sensor needs to be replaced:
- remove the weight tray
- Disconnect the Picoflex connector;
- undo the two self-tapping screws (D, fig.2b) then remove the sensor from its mount-
ing;
- mount the new sensor, paying attention to the correct fixing direction of the sensor
itself;
- Check that the sensor is working correctly using programme 98 “Display internal sen-
sor function”.

14 Technical service manual
Replacing the distance zero position sensor (detects rest position of sensor
arm)
In the event of incorrect distance and diameter readings, check that the zero position
sensor functions correctly as described in chapter “98 Displaying internal sensor func-
tion”.
Check the following if the sensor (C, Fig. 2b) does not read:
- the connection flat;
- that the sensor is installed correctly in its housing (see fig.2b, picoflex connector fac-
ing towards rear of machine);
If the zero sensor must be replaced, proceed as described in the paragraph “Distance
sensor”.
In fact, the zero sensor is mounted on the distance sensor board.
Note:
should it be necessary to replace the flat cable of sensor (C, figure 2b), ensure that the
flat cable is reconnected correctly on the board (see fig.2c). The flat cable must be fas-
tened to the base leaving a sufficient length of free cable to allow the sensor to move
without the cable itself twisting around the shaft assembly pulley.
Fig.2c
Replacing/adjusting position of diameter microswitch
- With the measuring sensor in the rest position (fig. “Position 1 with lever fully for-
wards”), check that the microswitch actuator lever is not pressed (contacts 1 and 2
open).
- With the measuring sensor in the operating position (fig. “Position 2 with lever fully
backwards”), check that the microswitch actuator lever is sufficiently depressed to acti-
vate the microswitch. In this position, the actuator lever must still have at least 0.5 mm
of remaining free travel (contacts 1 and 2 closed). If the above conditions are not met,

Technical service manual 15
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adjust the position of the microswitch on its mounting.
- Perform the checks described above with a tester. If these checks do not rectify the
problem, replace the microswitch, ensuring that the two contacts are reconnected
correctly as shown in figure 2d. To replace the microswitch, loosen the two screws (A,
figure 2d).
- Check the cable connecting the microswitch to the board.
Fig.2d
IMPORTANT
In the event of any work on the measurement sensor, the measurement sensor itself
must be calibrated as indicated in the use and maintenance manual.
- Check that the distance and diameter values read are correct, using wheels with
known dimensions or a special tool. To set the aforementioned values with a precision
of a tenth of an inch, on the display, select “OFF” for rounding to the nearest inch of
the diameter values read by the automatic sensor display as described in chapter “91
Thresholds and rounding”. The maximum error allowed for a wheel with a steel rim and
of medium dimensions is +/- 0.2 inches.
Notes
Please note that the nominal diameter of a wheel (e.g. 14”) refers to the tyre bead
contact surface, which is inside the wheel rim itself. The values measured are with
reference to external planes and, as a result, aresmaller than the nominal values
due to the thickness of the rim itself. The correction value therefore refers to an
average thickness of the rim. This means that the data measured on wheels with
different thicknesses may vary slightly (2 or 3 tenths of an inch maximum) from the
rated values. This is not a lack of accuracy of the measuring devices, but reflects
reality.

16 Technical service manual
REPLACING AND ADJUSTING THE PICK
UPS
- Open the weight-holder lid, first undoing the fixing screws.
- Remove the plastic guard of the central unit.
- Disconnect the pick up cable from the motherboard.
- Undo the two M8 dowels and remove the pick ups.
- Fit the new pair of pick ups, taking care that the two balls locate correctly inside the
recesses provided, then tighten the fixing dowels so that the pick ups move with just
a little friction.
Fit the pick ups marked I on the right and those marked E on the left (working from a
position facing the front of the machine).
- Reconnect the pick up cable.
Checks to ensure that the pick ups are operating correctly:
- Select the service program “96” to display the pick up data;
- fit an average-size 4WD wheel (e.g. 6 x 15” ) on the balancing machine and balance it
as accurately as possible.
- Imbalance the wheel by applying 100 grams (3.5 oz) to its outside.
- Perform a wheel spin to check the pick up signal values and synchronisation;
The values to be checked are the following:
- pick up synchronisation difference F from -2.0 to +2.0
- internal pick up signal I from 200 to 280
- external pick up signals E from 110 to 170
If the values displayed at the end of the wheel spin are not within the specified ranges,
adjust the dowels to regulate the tightness of the pick ups until the conditions are met.
These values are normally obtained with a tightening torque of about 2 Nm.
- Tighten the lock-nuts into a block then undo them slightly (about one side of the
hexagon) so that the Belleville washers present are operational.
During this operation the respective dowels should be kept still so that the pick up
preload conditions remain unchanged.
- Close the weight-holder lid and the plastic guard of the central unit again;
- Perform sensitivity calibration both in CAR environment with a car wheel and in
TRUCK environment with a truck wheel.
REPLACING THE CENTRAL UNIT
After making sure that the unit is really the cause of the machine’s malfunctions, re-
place it as described below:
- Open the weight-holder lid, first undoing the fixing screws.
- Remove the plastic guard of the central unit.
- Disconnect the sensor rod return spring from the body of the machine, unscrew the
fixing screws and remove the sensor from its seat. To access the return spring, remove
the protective cap close to the adjuster foot on the back of the machine.
- Disconnect the brake cylinder air line.
- Remove the motor and its support by unscrewing the three screws fixed to the beam

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(as described in the relative paragraph).
- Disconnect the connector on the search circuit board and the pick up cable on the
motherboard.
- Unscrew the three fixing screws on the beam and remove the central unit.
- Fit the new central unit. The three fixing screws must be tightened to a torque of 48 Nm.
- Replace the search circuit board complete with support.
- Reconnect the pick up and search board connectors.
- Replace the motor complete with support and adjust the wheel spin device.
- Replace the sensor, reversing the operations carried out to disconnect it.
- Calibrate the sensor as described in the operator’s manual.
- Perform a few wheel spins and check that the wheel spin device is operating correctly.
- Perform sensitivity calibration both in CAR environment (with a car wheel) and in
TRUCK environment (with a truck wheel).
ADJUSTING THE WHEEL SPIN DEVICE
- Open the weight-holder lid, first undoing the fixing screws.
- Undo the lock-nut (D, fig. 3) which fixes the adjuster washer (A, fig. 3).
- Completely tighten the adjuster check nut (D, fig. 3). This eliminates the preload of
the spring (B, fig 3).
- Undo the screws which fix the motor support (C, fig. 3) to the beam underneath.
- Position the motor unit so that the drive roller and the pulley are about 4-5 mm apart
and the axis of the motor is parallel to that of the central unit.
- Tighten the screws which fix the motor support.
- Preload the spring (B, fig. 3), unscrewing the check nut (D, fig. 1); until the gap be-
tween the drive roller and the pulley has been reduced to 2 mm.
- Tighten the lock-nut.
- The wheel spin device has a limit stop screw which dampens the residual oscillations
of the drive unit at the end of the wheel spin phase.
Adjust the limit stop as follows:
•positionthescrewsothatitisnottouchingtheleafspring;
•makesurethatthedriveunitisintherestposition(driveroller2mmfromthepul-
ley);
•tightenthescrewuntilitslightlypreloadstheleafspringofthemotorsupport;
- Perform a few trial wheel spins and check that the wheel spin device is operating cor-
rectly.
- Close the weight-holder lid again.
- If the screw (E, Fig.3) does not slide freely when activating the cylinder, turn the nut
(F, Fig.3).

18 Technical service manual
Fig.3
REPLACING THE WHEEL SPIN MOTOR
AND/OR ROLLER
- Open the weight-holder lid, first undoing the fixing screws.
- Disconnect the motor cables from the PEAC circuit board connector.
- Undo the lock-nut which fixes the adjuster washer.
- Completely tighten the adjuster check-nut (D, fig. 3). This eliminates the preload of
the spring (B, fig 3).
- Undo the screws which fix the motor support (C, fig. 3) to the beam underneath and
remove the motor-support assembly.
- Check the state of the drive roller and reuse it on the new motor only if it is in perfect
condition.
- Remove the roller by undoing the screw on the top.
- Apply medium thread glue to the locking screw and fit the roller on the new motor.
- Undo the screws which fix the motor to the support and replace it with the new one.
- Replace the motor-support unit on the supporting beam and adjust the wheel spin/
braking device as described in “Adjusting the wheel spin device”.
- Reconnect the motor power supply cables.
- Perform a wheel spin to check that the motor is operating correctly. Take any correc-
tive measures necessary.
- Close the weight-holder lid again.

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REPLACING THE BRAKE SHOES
- Open the weight-holder lid, first undoing the fixing screws.
- Remove the plastic guard of the central unit.
- Remove the search circuit board (B, fig. 4) from the supporting brake (C, fig. 4).
- Disconnect the motor power supply cable.
- Remove the wheel spin device and the motor unit.
- Disconnect the sensor rod return spring from the body of the machine, unscrew the
fixing screws and remove the sensor from its seat. To access the return spring, remove
the protective cap close to the adjuster foot on the back of the machine.
- Remove the pulley (D, fig. 4), unscrewing the two fixing dowels (E, fig. 4).
- Remove the brake shoes (A, fig. 4);
- Fit the new shoes.
- Apply medium thread glue to the locking dowels and replace the pulley.
- Turn the shaft by hand and check that the shoes do not touch the pulley when they
are in the rest position.
- Replace the search circuit board, the motor-support unit and the wheel spin device.
- Adjust the wheel spin device as described in “Adjusting the wheel spin device”.
- Replace the sensor, reversing the operations carried out to disconnect it.
- Calibrate the sensor as described in the operator’s manual.
- Perform a few wheel spins and check that the wheel spin device is operating cor-
rectly.
- Fit a truck wheel and check that the brake is working correctly.
- Close the weight-holder lid again.
B
C
E
D
A
Fig.4

20 Technical service manual
TROUBLESHOOTING
The balancing machine features autotest and autodiagnostics programs which provide in-
formation about most possible failures and the relative corrective measures (refer to the
list of error messages and the “Troubleshooting” section in the operator’s manual).
However, there are malfunctions which the machine is not able to recognise; a list of
them is provided below.
WARNING
For all electrical malfunctions, before replacing a circuit board the following should
always be checked:
- that the power supply is connected to the transformer primary correctly for the mains
voltage available.
- that the voltages of the transformer secondaries are at the specified rated values (use
a tester set as AC voltmeter and refer to the drawing of the transformer enclosed);
- that the wiring between the components probably involved in the malfunction is un-
damaged. In particular, check:
•thattheconnectorsarettedcorrectly;
•thatthecontactsarexedcorrectlytotheendsoftheindividualwiresofthecables;
•thatthemainsvoltageinthezonewherethemachineisinstalledisstableandthat
the workshop’s earth connection system is in good working order;
•thattheprotectivefusesonthetransformerandonthepowersupplycircuitboard
have not blown, and that the LEDs on the power supply board which indicate that
the various power supply voltages are available illuminate.
The following is a summarising table, with reference to the general electrical wiring
diagram.
THE MACHINE DOES NOT SWITCH ON
Use a voltmeter to check that the power supply voltage is reaching the terminal board
of the transformer primaries.
1) If the voltage is not present on the primaries, check:
- that the power supply socket and the relative protective fuses are in good order;
- that the plug is correctly connected to the machine’s power cord;
- that the mains power cord is undamaged;
- that the master switch is operating correctly.
2) If the voltage is present on the primaries check:
- that the transformer fuses have not blown;
- that the specified voltages are present on the transformer secondaries;
- that the power supply and PEAC control circuit board is working correctly, checking
that the fuses on the board have not blown and that the relative indicator LEDs illu-
minate;
- that the motherboard power supply cable is wired correctly and its connectors are
connected correctly;
- for short-circuits on the peripherals. To do this, disconnect all the cables from the
motherboard connectors except for the power supply cable and try to switch on the
machine;
If the checks listed above do not reveal faulty components, replace the motherboard.