Precor 9.55 User Manual

9.55 Treadmill

Page 1

9.55 Treadmill

Warning: This service manual is for use by Precor trained service providers only.

If you are not a Precor Trained Servicer, you must not attempt to service any Precor Product;

Call your dealer for service.

This document contains information required to perform the majority of troubleshooting, and
replacement procedures required to repair and maintain this product.

This document contains general product information, software diagnostic procedures (when
available), preventative maintenance procedures, inspection and adjustment procedures,
troubleshooting procedures, replacement procedures and electrical block and wiring diagrams.

To move directly to a procedure, click the appropriate procedure in the bookmark section to the
left of this page. You may “drag” the separator bar between this page and the bookmark section
to change the size of the page being viewed.

© 2003 Precor Incorporated
Unauthorized Reproduction and Distribution Prohibited By Law

9.55 Treadmill

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Section One - Things you Should Know

About This Appendix

The 9.55 has been manufactured in two versions. When servicing a 9.55 it is critical that you are
aware of which version of version you are servicing. The differences in the versions may greatly
impact service requirements and procedures. For convenience, the versions detailed below will
be referred to as version 1 or version 2 in the reminder of this service manual. Any procedures
that do not reference a specific version is applicable to all versions of the 9.55.

Version 1 was manufactured between March 2000 and July 1, 2001.
Version 2 was manufactured between July 2, 2001 and the present.

Section One, Things You Should Know. This section includes technical specifications. Read

this section, as well as the 9.55 Treadmill Owner’s Manual, before you perform the maintenance
procedures in this manual.

Section Two, Software Features. Precor’s 9.55 Treadmill is programmed with several
diagnostic and setup features. This section contains the procedures you need to access the
diagnostic features on this treadmill.

Section Three, Checking Treadmill Operation. This section provides you with a quick way of
checking treadmill operation. Check treadmill operation at the end of a maintenance procedure
and when it is necessary to ensure that the treadmill is operating properly.

Section Four, Inspection and Adjustment Procedures. Perform inspection procedures when
a trouble symptom points to a particular problem and after removing and replacing major
components. Many maintenance problems can be fixed by adjusting various treadmill
components. This section also provides you with the step-by-step procedures required to make
these adjustments.

Section Five, Troubleshooting Procedures. The diagnostic and troubleshooting procedures
contained in this section should be performed when it is necessary to isolate a problem to a
particular component.

Section Six, Replacement Procedures. When a treadmill component must be replaced, go to
this section and follow the step-by-step procedures required to remove and replace the
component.

Section Seven, Technical Diagrams and Parts Lists. This section includes wiring diagrams,
and block diagrams for the 9.55 Treadmill.

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General Information

For the latest exploded view diagram, part number and part pricing information, visit the Precor
dealer website at “www.precor.com/Dealer”.

Technical Specifications

Physical Specifications

Length: 84 inches (213 cm.)

Width: Handrails 36.75 inches (93 cm.)

Base 33.75 inches (86 cm.)
Height: 55 inches (140 cm.)
Running surface: 26 inches by 60 inches (51 cm. by 152 cm.)
Motor: 2 hp. continuous duty DC
Speed: 0.5 to 12 mph (0.8 to 19 kph)

10 mph is equivalent to a 6 minute mile
Incline: 0% to +12% grade
Power: 120 Vac 50/60 Hz @ 20 amp

240 Vac 50/60 Hz @ 20 amp
Weight: 350 lbs (158 kg.)
Shipping Weight: 460 lbs (207 kg.)

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Procedure 2.1 - Accessing the Hardware Validation Program

The treadmill's diagnostic program consists of the following modes:

• Display Test

• Keyboard Test

• Heart Rate Test

• Lift Test

• Belt Speed Test

• Belt Power Test

• Circuit Breaker Test

Procedure

1. The keys on the display are hypothetically numbered 1 to 7 from left to right. See Diagram

2.1. The STOP is key number 4 and is located directly below the QUICK START key. The
QUICK START key is not part of the numbering sequence.

2. Plug the power cord into the wall outlet, then turn on the treadmill with the circuit breaker.

3. Press keys RESET,5,1,7,6,5,7,6,1, sequentially.

4. The display will momentarily read DIAGS - HARDWARE VALIDATION.

5. The display will momentarily read DISPLAY TEST and then illuminate every LED on the
display. Check all LED positions to ensure that all of the LED’s are functioning. Press the

ENTER key to continue.

Diagram 2.1 - 9.55 Treadmill Display

Key #7

Key #4

Reset/Key #1

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6. The display will momentarily read KEYBOARD TEST.

7. The keyboard test will place two dots on the display for each key on the display, including
the numeric keypad. Pressing a key will cause the upper of the two dots associated with the
key to go out. Test all of the keys in this manner. Tug on the safety key lanyard, to ensure
that the STOP key is activated.

8. Press and hold the ENTER key to proceed to the heart rate test.

9. The display will momentarily read HEART RATE TEST.

10. The heart rate test will display the heart rate being received during this test from either a
chest strap transmitter or test transmitter.

11. Three heart rate values will be displayed. They will be prefixed “U” for unfiltered, “F” for
filtered and “P” for Polar filtering. The Polar filtered heart rate will also appear in the normal
heart rate display, since Polar filtering is the filtering used during normal operation. The right
most red LED in the smart rate display will flash each time a heart beat is detected.

Note: If there is not a heart rate receiver installed or there is a bad or intermittent connection

between the heart rate receiver and the upper PCA, the messages in step 9 will be
replaced by the message NO HEART RATE RECEIVER.

12. Press the ENTER key to proceed to the lift test.

13. The display will momentarily read LIFT TEST.

14. Two numbers will be displayed, the percent of lift and A/D number related to the current lift
position. The A/D (analog to digital) number represents the lift potentiometer reading. The A/
D number will be in the range of 0 to 255.

15. The lift may be operated using the INCLINE keys. The incline percentage and A/D numbers
will change accordingly. Care must be taken while operating the lift in this mode because
the normal upper and lower range limits are not in effect. It is possible to operate the lift to
it’s physical limits and may cause the lift motor to jam.

16. The A/D reading will be used later in this service manual to calibrate the lift.

17. Press the ENTER key to proceed to the belt speed test.

18. The display will momentarily read BELT SPEED TEST.

19. The speed of the running belt is controlled by the SPEED keys during this test.

20. The following values are displayed; time (that the running belt has operated during this test),
current (in amps through the drive motor), belt speed (in MPH) and power bits (PWM value).

21. This test is valuable in diagnosing treadmill load conditions such as running bed and/or
running belt condition. As load is increased, the speed is kept at a constant value (as set via
the SPEED keys) and the current and power bits will vary proportionately to the load.

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22. It is suggested that you perform this test on a treadmill known to be in excellent operating
condition. Note the values displayed at a fixed speed (such as 3 MPH) and your body
weight. Those values may then be used to benchmark the operation of treadmills you are
diagnosing.

23. Press press the ENTER key to proceed to the belt power test.

24. The display will momentarily read BELT POWER TEST.

25. The belt power test is similar to the belt speed test except that the SPEED keys control the
power bits (PWM value) instead of the belt speed.

26. The same (see step 16) values will be displayed as in the belt speed test.

27. This test is valuable in diagnosing treadmill response to load conditions. As load is
increased, the power bits are kept at a constant value (as set via the SPEED keys) and the
current and belt speed will vary proportionately to the load.

28. It is suggested that you perform this test on a treadmill known to be in excellent operating
condition. Note the values displayed at a fixed power bit reading (as set by the SPEED
keys) and your body weight. Those values may then be used to benchmark the operation of
treadmills you are diagnosing.

29. Press the ENTER key to proceed to the circuit breaker test.

30. The display will momentarily read CIRCUIT BREAKER TEST.

31. The message HOLD ARROW KEY TO TRIP will be displayed. When the arrow key is held,
the message BREAKER WILL TRIP 3 2 1 0 will flash on the screen one word at a time.
Shortly after the 0 is displayed, the circuit breaker will trip. If the arrow key is released before
the circuit breaker trips, the test will be terminated.

32. The circuit breaker test is the last test in the diagnostics routine. If you do not wish to ca use
the circuit breaker to trip, press the RESET or the ENTER key to exit the diagnostics routine.

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Procedure 2.2 - Accessing the Information Display Program

The information display will access the following data;

• Odometer

• Hour meter

• Software version

• Error log

Procedure

1. Plug the power cord into the wall outlet, then turn on the treadmill with the circuit breaker.

2. Press the keys RESET,6,5, sequentially.

3. The display will momentarily read, DIAGS - INFORMATION DISPLAY.

4. The display will momentarily read, ODOMETER.

5. The treadmill’s odometer will be displayed as 1234567 MPH or 1234567 KPH.
Note: The odometer data is stored in non-volatile memory on the upper PCA. If the upper PCA

is replaced the odometer data will be lost.

6. Press the ENTER key to proceed to the hour meter display.'

7. The display will momentarily read, HOUR METER.

8. The operating time of the unit will be displayed as 12345 HOURS. The operating time is
defined as total amount of time that the unit has operated in program modes with the drive
motor running. The hour meter is also used to provide the “time stamp” for the error code
log.

9. Press the ENTER key to proceed to the software version display.

10. The display will momentarily read, SOFTWARE VERSION.

11. The software versions of the upper and lower PCA’s will be displayed as;

UPPER 1.01 LOWER 1.01.

12. Press the ENTER key to proceed to the error log.

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13. The error log will store up to 10 error conditions. The errors are logged with the most recent
error in position one. When a new error condition occurs, each existing error is pushed down
one position in log. If there was an error in position 10 when a new error was logged, the
error that was in position 10 will be lost.

14. Each error in the log will show the odometer reading (in miles) and the time (hour meter)
when the error occurred. The errors are displayed as;

1 ER20 1234567 MI 12345 HRS.

15. The arrows keys will allow you to scroll through the log. When the first unused position is
reached in the log, the message NO MORE ERRORS will be displayed.

16. When the QUICK START key is held for 2 seconds the message HOLD TO CLEAR
ERRORS will be displayed. If the QUICK START key is held for an additional 2 seconds, the
message CLEARED will be displayed. When the QUICK START key is released the
message NO MORE ERRORS will be displayed and all error are erased from the log.

17. Press the RESET the ENTER key to exit the information display.

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Procedure 2.3 - Accessing the User Parameter Program

This procedure allows you to change the following settings:

• Set Measurement Units

• Enable/Disable Password

• Set User Name

Procedure

1. Plug the power cord into the wall outlet, then turn on the treadmill with the circuit breaker.

2. Press keys RESET,5,6,7,1 sequentially.

3. The display will momentarily read, DIAGS - SET USER PARAMETERS.

4. The display will momentarily read SELECT UNITS

5. The currently selected measurement unit will then be displayed.

6. Use the

▲,▼ keys to scroll through the available measurement units.

7. Press the ENTER key to select the currently displayed measurement unit.

8. The display will momentarily read, PASSWORD

9. Use the

▲,▼ keys to select either PASSWORD ENABLED or PASSWORD DISABLED.

10. Press the ENTER key to continue.

11. The display will momentarily read, USER NAME.

12. Up to four user names may be entered. If user names have not been p reviously entered the
default user names will be USER1, USER2, USER3 and USER4.

13. The USER1 name will be displayed first. The ENTER key will select USER2, then USER3,
then USER4.

14. With the user name to be edited displayed, use the INCLINE

▲, INCLINE ▼, to select the

character position to be edited. Use the SPEED

▲, SPEED ▼ keys to select the letter to be

placed in the selected character position. The user name can be a maximum of five
characters.

15. Press the ENTER key to select the next user name or to exit the program.

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Procedure 2.4 - Documenting Software Problems

When a problem is found with the software in the upper or lower PCA, record the information
listed below.

When a problem occurs, record the following information:

• Model and serial number

• Software version number

• Program number running when the problem occurred

• A description of:
a. What happened or failed to happen.
b. The action taken by the user just before the problem occurred.
c. Problem-related information (such as how far into the program the problem occurred,

the work level being used when the problem occurred, etc.).

• The frequency of occurrence.

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Section Three - Checking Treadmill Operation

This section provides you with a quick method of checking treadmill operation. Check treadmill
operation at the end of a maintenance procedure and when it is necessary to ensure that the
treadmill is operating properly.

Procedure

4. Plug the power cord into the wall outlet, then turn on the treadmill with the circuit breaker.

5. Place the treadmill in Manual Mode. Adjust the speed of the running belt to 2–3 m.p.h.
Operate the treadmill for at least 5 minutes.

a. Concentrate on the feel of the running belt and the sound of the drive motor and rollers.

Be on the alert for unusual noises, smells, or vibrations.
b. Log the power bits under loaded and unloaded conditions.
c. Observe the LED’s on the electronic console. Make sure that each LED lights as the in-

formation corresponding to that LED is displayed on the electronic console.

3. If during step 1c, squeaking noises associated with the running deck were heard, check the
lubrication of the running deck studs. If necessary, apply silicon grease to all of the running
deck studs.

3. Press the STOP key. When the treadmill comes to a stop, view the electronic console as the
treadmill scans time, speed, distance and percent of lift.

4. Press the INCLINE ▲ key while viewing the electronic console. Confirm that the running
bed inclines and the incline display increments to 12% as the INCLINE ▲ key is pressed.

5. Press the INCLINE ▼ key while viewing the electronic console. Confirm that the running bed
returns to a level position and the incline display decrements to 0% as the INCLINE ▼ key is
pressed.

6. Turn off the treadmill with the circuit breaker, then unplug the treadmill from the wall outlet.

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Procedure 4.1 - Calibrating the Lift Motor

1. Set the treadmill circuit breaker in the “off” position and unplug the line cord from the wall
outlet.

2. Remove the hood.

3. Place the treadmill on it’s right side. Remove hitch and clevis pins that secure the lift tube t o
the lift platform. See Diagram 4.1.

Diagram 4.1 - Lift Motor Mounting

Hitch Pin

5/8”

Hitch Pin

Clevis Pin

Lift Tube

Drive Screw

Clevis Pin

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4. Plug the power cord into the wall outlet, set the treadmill circuit breaker in the “on” position.

5. Press keys RESET, 5,1,7,6,5,7,6,1, sequentially to enter the diagnostics routine. Refer to
Procedure 2.1 and advance to the lift test. When the lift calibration number is displayed on
the console, use the INCLINE

▲ or INCLINE ▼ key to set the lift calibration number to 20.

CAUTION

While running the lift motor in the diagnostics mode it is possible to operate the lift motor beyon d
it’s normal range of motion. When you perform the next step, care must be taken not to jam the
lift tube against the motor frame.

6. Press the RESET key to exit the diagnostics mode.

7. Set the treadmill circuit breaker in the “off” position, unplug the line cord from the wall outlet.

8. Rotate the lift tube clockwise, by hand, as far as possible. Then rotate the lift tube counter­clockwise until the distance from the top of the lift tube to the lift motor is 5/8 inch. See
Diagram 4.1. While rotating the lift tube, be sure the lift motor drive screw does not rotate. If
the drive screw is rotated, return to step 4 and repeat steps 4 through 7.

9. Replace the clevis and hitch pins removed in step 3. Return the treadmill to an upright
position.

10. Plug the line cord into the wall outlet, set the treadmill circuit breaker in the “on” position.

11. check the calibration of the lift system by performing the following steps:
a Press the INCLINE

▲ key until the console displays 12% incline.

b Press the INCLINE

▼ key to return to 0% incline.

12. Re-install the hood.

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Procedure 4.2 - Adjusting Drive Belt Tension

1. Set the treadmill circuit breaker in the “off” position and unplug the line cord from the wall
outlet.

2. Remove the hood.

3. Place the drive belt tension gauge on the drive belt as shown in Diagram 4.2.

Diagram 4.2 - Drive Belt Tension Gauge

4. The gauge should read approximately 80 inch/pounds. The drive belt tension is acceptable
if it is in the range of 70 to 90 inch-pounds.

5. If the drive belt tension is less than 70 or greater than 90 inch/pounds, adjust the drive belt
adjustment bolt until the belt gauge reads approximately 80 inch/pounds. See Diagram 4.3.
Momentarily remove the drive belt tension gauge from the drive belt. Replace the drive belt
tension gauge on the drive belt and re-adjust the drive belt tension, if necessary.

6. Re-install the hood.

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Diagram 4.3 - Drive Belt Adjustment Bolt

7. Plug the line cord into the wall outlet and set the treadmill circuit breake r in the “on ” positio n.

8. Check treadmill operation per Section 3.

Drive

Motor

Drive Belt

Adj. Bolt

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Procedure 5.1 - Troubleshooting the Keypad and Upper PCA

If the function keys on the electronic console are unresponsive, the problem may be either the
upper PCA or keypad. The keys on this unit are touch sensitive keys. It is necessary to use the
keypad diagnostics to troubleshoot the key functions.

Procedure

1. Set the circuit breaker in the “off” position.

WARNING

Before continuing with this procedure, review the Warning and Caution statements listed in
Section One of the Commercial Treadmill Service Manual.

2. If the treadmill powers up and functions normally until a particular key(s) is pressed, skip to
step 11.

3. If a “key depressed” message is immediately displayed when the treadmill is powered up,
continue with the next step.

4. This condition may be caused by either the keypad or upper PCA. Set the circuit breaker in
the “off” position.

5. Remove the four screws that fastens the display housing front panel to the display housing
backing plate. These screws are located on the rear of the display housing backing plate.

6. Lift the display housing front panel off of the display housing backing plate. Remove the
keypad connector from the upper PCA. See Diagram 5.1.

Diagram 5.1 - Upper PCA & Keypad

Upper PCA

Keypad

Connector

Keypad

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7. Set the circuit breaker in the “on” position.

8. If a “key depressed” message is immediately displayed when the treadmill is powered up,
replace the upper PCA.

9. If a “key depressed” message is not displayed when the treadmill is powered up, replace the
display housing front panel. The display housing front panel is equipped with the keypad.

10. If you have performed all of the procedures above and have been unable to correct the
problem, call Precor customer service.

11. Access the diagnostics program per procedure 2.1. If the key(s) necessary to access the
diagnostic program is not functioning, skip to step 14.

12. Test the keypad per Procedure 2.1, step 6.

13. If all of the keys test good, the problem may be user error or a key function that is normally
disabled during a particular user program.

14. If one or more keys do not function correctly, either the keypad (display housing) or upper
PCA could be defective. Replace the display and repeat step 12. If the display housing did
not correct the problem, re-install the original display housing and replace the upper PCA.

15. If you have performed all of the procedures above and have been unable to correct the
problem, call Precor customer service.

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Procedure 5.2 - Troubleshooting the Lift System

Lift System Description:

The lift system on these units consists of an AC line voltage driven lift motor (120 Vac or 240
Vac), and an internal 1 KΩ potentiometer for lift position identification. The lift motor contains two
motor windings, one to operate the motor in an “upward” direction and the other to operate the
motor in a “downward” direction. As the lift motor is operated, the motor also rotates the
potentiometer via an internal gear system. Therefore, the position of the lift system can be
determined by monitoring the value of the internal potentiometer. The lift motor is initially set at a
known starting position (calibration, See Procedure 4.1), subsequent motor movement is tracked
via the potentiometer resistance reading.

Note:

All resistance measurements must be performed with power removed from the treadmill.
Performing resistance measurements with voltage applied may damage your ohmmeter.

Procedure

1. If the lift motor operates but creates a lift error (error 40 or 42) go to step 16. If the lift motor
will not move continue with step 2.

2. Set the treadmill’s circuit breaker in the “off” position and remove the AC line cord from the
AC outlet.

3. Remove the F2 (Lift AC) fuse from the lower logic PCA. Using an ohmmeter, check the
resistance of the F2 fuse. See Diagram 5.2. The fuse should measure approximately 0.1 Ω
or less. If the fuse is open or high resistance, replace the fuse.

Diagram 5.2 - Lower Logic PCA

System

Fuse

Fuse

Fuse

Fan

Lift

F1

F3

F2

“Up” LED

“Down” LED

J5, Term 1

Fan Wires

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4. Insert the treadmill’s line in the AC outlet and set the circuit breaker in the “on” position. Set
the treadmill in the manual program and press the LIFT

▲ key. If the lift motor operates

normally, test treadmill operation per Section 3. If the lift motor still does not operate, retest
the lift fuse per steps 2 & 3. If the fuse is open again, continue with step 13. If the fuse is
good continue with step 5.

5. Connect an AC voltmeter between terminals 1 & 3 of the J5 connector. See Diagram 5.2.
Set the treadmill in the manual program and press the LIFT

▲ key. The AC voltmeter

should read AC line voltage (either 120 Vac or 240 Vac) and the UP LED should illuminate.
Note that the AC line voltage reading will only be present before an error condition is
displayed.

6. If the F2 fuse is good and the UP LED illuminates and the AC voltmeter does not read the
presence of AC line voltage replace the lower logic PCA per Procedure 6.3.

7. If the UP LED does not illuminate and the display indicates that the lift should be moving
upward, replace the upper PCA per Procedure 6.8.

8. If the AC voltmeter reads the presence of AC line voltage and an error 40 is displayed, go to
step 10.

9. If the AC voltmeter reads the presence of AC line voltage and an error 42 is displayed,
continue with step 11.

10. Set the treadmill’s circuit breaker in the “off” position and remove the AC line cord from the
AC outlet. Remove the lift motor connector from the J5 connector on the lower logic PCA.
Visually. inspect the lift motor connector for broken or improperly crimped connections.
Using an ohmmeter, read the resistance between terminals 1 & 4 and between terminals
3 & 4. Both readings should be approximately 15 Ω. If either reading is open or very high
resistance, replace the lift motor per Procedure 6.1.

11. Set the treadmill’s circuit breaker in the “off” position and remove the AC line cord from the
AC outlet. Remove the lift motor connector from the J1 connector on the lower logic PCA.
Visually inspect the lift motor connector for broken or improperly crimped connections.
Using an ohmmeter, measure between terminals 1 & 3, 1 & 2 and 2 & 3 of the lift motor
connector. Terminals 1 and 3 should read approximately 1 KΩ. The sum of the two readings
between terminals 2 & 3 and 1 & 2 should total approximately 1 KΩ. If either reading is open
or very high resistance, replace the lift motor per Procedure 6.1.

12. If you have performed all of the procedures above and have been unable to correct the
problem, call Precor customer service.

13. Set the treadmill’s circuit breaker in the “off” position and remove the AC line cord from the
AC outlet. Remove the lift motor connector from the J5 connector on the lower logic PCA.
Visually inspect the lift motor connector for broken, frayed or improperly crimped
connections. Using an ohmmeter, read the resistance between terminals 1 &4, 3 & 4 and
1 & 3. The readings should be approximately 15 Ω, 15 Ω and 30 Ω, respectively. If the
reading is significantly low, replace the lift motor per Procedure 6.1.

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14. If the resistance readings in step 13 are normal, replace the lower logic PCA per Procedure

6.3.

15. If you have performed all of the procedures above and have been unable to correct the
problem, call Precor customer service.

16. Set the treadmill’s circuit breaker in the “off” position and remove the AC line cord from the
AC outlet. Remove the lift motor connector from the J1 connector on the lower logic PCA.
Visually inspect the lift motor connector for broken or improperly crimped connections.
Using an ohmmeter, measure between terminals 1 & 3, 1 & 2 and 2 & 3 of the lift motor
connector. Terminals 1 and 3 should read approximately 1 KΩ. The sum of the two readings
between terminals 2 & 3 and 1 & 2 should total approximately 1 KΩ. If either reading is open
or very high resistance, replace the lift motor per Procedure 6.1.

17. If the resistance measurements in step 16 are normal, the problem may be either the lower
logic PCA or the upper PCA. Replace the lower logic PCA. If the problem persists, reinstall
the original lower logic PCA and replace the upper PCA.

18. If you have performed all of the procedures above and have been unable to correct the
problem, call Precor customer service.

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Procedure 5.3 - Troubleshooting the Speed Sensor

Note:

The speed sensor is a hall effect sensor that emits a pulse when a flywheel lobe passes between
it’s transmitter and receiver. The speed control circuit processes the pulse train emitted by the
speed sensor. The speed sensor signal is a real time representation of the operating speed of
the treadmill. The speed control circuit compares the real time speed (speed sensor output) with
the speed that it expects the treadmill to be operating a t an d a cts a cco rdingly to control treadmill
speed or initiate an error code sequence, if necessary. Typically, if a problem exists with the
speed sensor the drive motor will operate (perhaps only briefly) before a speed related error
occurs (errors 20-26).

1. Set the treadmill circuit breaker in the “on” position. Using a DC voltmeter, measure the
voltage between terminal 3 of J2 (green wire) and terminal 4 of J2 (black wire) on the lower
logic PCA. Slowly, rotate the drive motor flywheel. The voltage should read approximately 5
Vdc when a flywheel lobe is between the speed sensor “legs” and approximately 0.25 Vdc
when a flywheel lobe is not between the speed sensor “legs”.

Diagram 5.3 - Speed Sensor Mounting

2. If the voltages in step 1 are correct, go to step 5. If the voltage in step 1 is 0 Vdc or
significantly low when a flywheel lobe is between the speed sensor “legs’, continue with step

3.

3. Measure the voltage between terminal 1 of J2 (red wire) and terminal 4 of J2 (black wire) on
the lower PCA. The voltage should read approximately 5 Vdc.

Flywheel

Speed

Sensor

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4. If the voltage is missing or significantly low, disconnect the speed sensor plug from the lower
PCA. Measure the voltage between pins 1 & 4 of the J2 plug on the lower PCA. If the
voltage is approximately 5 Vdc, replace the speed sensor. If the voltage is missing or
significantly low, replace the lower logic PCA.

5. At this point the speed sensor output is good, but a speed error occurs. There are two
potential causes for this condition. They are upper PCA or lower logic PCA. There are no
good means of troubleshooting these components other than substituting known good
components. Replace only one component at a time. If the component that you replaced
does not correct the problem, replace the original component. Try substituting the lower
logic PCA first then the upper PCA, if necessary.

6. If you have performed all of the above procedures and have been unable to correct the
problem, call Precor Customer Support.

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Procedure 5.4 - Troubleshooting the External A.C. Power

Source

It is extremely important that any Precor treadmill be connected to and operated on a dedicated
20 amp A.C. circuit. A 20 amp dedicated circuit is defined as: a circuit fed by a 20 amp circuit
breaker that feeds a single load. A treadmill operating from a non-dedicated circuit or a circuit
breaker of less than 20 amps capacity will not have the necessary power available to operate
normally under higher load conditions. The lack of available power can cause any number of
symptoms ranging from numerous intermittent (seemingly inexplicable) error conditions, poor
speed control, or tripping the house circuit breaker.
If any of the above symptoms exist the external A.C. circuit must be checked and confirmed to be
a 20 amp dedicated circuit before

troubleshooting the treadmill.
In addition the A.C. voltage must be checked. Nominal A.C. operating voltage on 120 Vac circuits
is 105 Vac to 120 Vac. Nominal A.C. operating voltage on 240 Vac circuits is 208 Vac to 240
Vac.
For operator safety considerations and to minimize electrostatic discharge conditions the A.C.
frame ground continuity must also be verified to be a low resistance connection to the A.C.
distribution ground bar.

Important

If the A.C. circuit feeding a treadmill is found to be a non-dedicated circuit or a circuit equipped
with a circuit breaker with a capacity of less than 20 amps, the A.C. circuit must be corrected to
be a 20 amp dedicated circuit before

any reliable troubleshooting can be performed on the
treadmill. More importantly, a non-dedicated circuit may constitute a safety hazard to the
treadmill operator.

120 Vac Systems

120 Vac distribution systems utilize a single pole circuit breaker (hot lead) and a neutral lead
connected to a common neutral (ground) bar. The A.C. safety ground (green wire) is connected
to a separate ground bar in the distribution system.

The most common problems found are (1) the circuit is fed by a circuit breaker of less than 20
amp capacity, (2) the circuit breaker correctly feeds a single A.C. outlet but the neutral is
common between several A.C. outlets and (3) both the hot and neutral leads feed several A.C.
outlets. The appropriate correction action or actions (see below) must be followed if any of the
above conditions exist. Corrective actions should only be undertaken by a licensed

electrician.

1. The circuit breaker feeding the treadmill is not a 20 amp circuit breaker.

If the circuit breaker is greater than 20 amps, the circuit breaker should be replaced with a
20 amp circuit breaker. If the circuit breaker is less than 20 amps the circuit breaker must be
replaced with a 20 amp circuit breaker and the wiring from the A.C. distribution must be
capable of safely handing 20 amps. If the A.C. wiring is under sized, it must be replaced
with wire capable of safely handling 20 amps. Please, refer to local electrical codes when
determining the appropriate wire size for a 20 amp circuit.

9.55 Treadmill

Page 1-24 Page 24

2. The circuit breaker correctly feeds a single A.C. outlet but the neutral is common
between several A.C. outlets.

The common neutral lead must be removed from treadmill’s A.C. outlet and a new neutral
lead from the treadmill’s A.C. outlet to the A.C. neutral distribution bar must be added.

3. Both the hot and neutral leads feed several A.C. outlets.

Both the common neutral and hot leads must be removed from treadmill’s A.C. outlet and a
new neutral lead and hot lead from the treadmill’s A.C. outlet to the A.C. neutral distributio n
bar and circuit breaker must be added.

240 Vac Systems

240 Vac distribution systems utilize a double pole circuit breaker (two hot leads) The A.C. safety
ground (green wire) is connected to a ground bar in the distribution system.
The most common problems found are (1) the circuit is fed by a circuit breaker of less than 20
amp capacity and (2) both the hot leads feed several A.C. outlets. The appropriate correction
action or actions (see below) must be followed if any of the above conditions exist. Corrective

actions should only be undertaken by a licensed electrician.

1. The circuit breaker feeding the treadmill is not a 20 amp circuit breaker.

If the circuit breaker is greater than 20 amps, the circuit breaker should be replaced with a
20 amp circuit breaker. If the circuit breaker is less than 20 amps the circuit breaker must be
replaced with a 20 amp circuit breaker and the wiring from the A.C. distribution must be
capable of safely handing 20 amps. If the A.C. wiring is under sized, it must be replaced
with wire capable of safely handling 20 amps. Please, refer to local electrical codes when
determining the appropriate wire size for a 20 amp circuit.

2. Both the hot leads feed several A.C. outlets.

Both hot leads must be removed from treadmill’s A.C. outlet and two new hot leads from the
treadmill’s A.C. outlet to the circuit breaker must be added.

A licensed electrician may use the followings hints to determine if an A.C. service is dedicated.

1. If, on a 120 Vac system, the A.C. distribution panel contains more circuit breakers than
neutral leads, the system has shared neutral leads and is not dedicated.

2. If an A.C. outlet (120 or 240 Vac) has multiple hot and/or neutral leads, it is not a dedicated.

If either of the above conditions exist, the system is not dedicated. However, absence of the
above conditions does not necessarily mean that the system is dedicated. If any doubt exists
about A.C. systems dedication, point to point tracing of the A.C. wiring may be the only way to
prove system dedication.

9.55 Treadmill

Page 25

Procedure 6.1 - Replacing the Lift Motor

Note:

The replacement lift motor must be calibrated prior to installation. The lower PCA bracket
assembly must be removed to gain access to the lift motor. The defective lift motor is then
removed and the calibrated replacement lift motor is installed. The lower PCA bracket is then
replaced.

1. If the incline is at 0%, skip to step 3.

2. Set the treadmill circuit breaker in the “on” position. Press the QUICK START to start the
running belt. Use the INCLINE

▼ key to lower the incline to 0%

3. Set the treadmill circuit breaker in the “off” position and remove the AC line cord from t he AC
outlet.

4. Disconnect the lift motor plugs from J2 and J5 connectors of the lower logic PCA. See
Diagram 5.2.

5. Lay the replacement lift motor on the floor in front of the treadmill and connect it’s two plugs
to the J2 & J5 connectors of the lower logic PCA.

6. Calibrate the lift motor per Procedure 4.1, steps 4-7.

7. Remove the lower PCA per Procedure 6.4, steps 1-7.

8. Remove the defective lift motor as follows: remove the screw that fastens the frame ground
wire (green with yellow stripe) to the treadmill frame. Remove the hitch and clevis pins from
the top and bottom of the lift motor. Remove the lift motor from the treadmill.

9. Set the calibrated lift motor in its mounting position. Replace the upper clevis and hitch pins.

10. Replace the lower clevis and hitch pins. It may be necessary to slightly rotate the lift tube to
align it so that the clevis pin may be inserted. To align the hole in the lift tube rotate it in the
direction that will cause the least amount of rotation to make alignment possible.

11. Connect the frame ground wire to the treadmill frame with the screw removed in step 6.
Route both lift motor cables as noted in the lift motor removal procedure.

12. Replace the lower PCA per Procedure 6., steps 8-12.

13. Route the lift motor cables to the lower logic PCA as noted during the previous removal
procedure. Plug the lift motor plugs into the J2 & J5 connectors on the lower logic PCA.

14. Check treadmill operation per Procedure 3.

9.55 Treadmill

Page 1-26 Page 26

Procedure 6.2 - Replacing the Lift Platform

1. Set the treadmill circuit breaker in the “off” position. Remove the AC line cord from the AC
outlet.

2. Remove the treadmill hood. Carefully, lay the treadmill on it’s right side.

3. Remove the hitch pin and clevis pin that fastens the lift motor tube to the lift platform. While
the lift tube is not fastened to the lift platform, care must b e taken to no t allow th e lift tu be to
rotate. If the lift tube rotates, the lift motor must be re-calibrated per Procedure 4.1.

4. Remove the four bolts (2 each side) that fasten the lift platform to the treadmill frame. See
Diagram 6.1. Remove the lift platform from the treadmill.

Diagram 6.1 - Lift Platform Mounting

5. Set the replacement lift platform in it’s mounting position. Start all four lift platform bolts.
Securely tighten all four lift platform bolts.

6. Fasten the lift platform to the lift motor tube with the clevis and hitch pins removed in step 3.
Do not allow the lift tube to rotate.

7. Check treadmill operation per Procedure 3.

Mounting
Bolt

9.55 Treadmill

Page 27

Procedure 6.3 - Replacing the Lower Logic PCA

Version 1 Lower Logic PCA’s are no longer available. If either the lower logic PCA or the lower
Power PCA requires replacement it must be replaced with the version 2 lower PCA assembly.
Version 1 units can be identified in two ways, the lower PCA assembly has two separate PCA’s
mounted on it and the serial number will indicate the unit was manufactured prior to July
2, 2001.

To replace the lower PCA on a version 1 9.55 treadmills, order (1) 59036-101 9.55 lower PCA
retrofit kit. The kit comes complete with all necessary parts and installation instructions.

9.55 Treadmill

Page 1-28 Page 28

Procedure 6.4 - Replacing the Lower Power PCA

Version 1 Lower Power PCA’s are no longer available. If either the lower logic PCA or the lower
Power PCA requires replacement it must be replaced with the version 2 lower PCA assembly.
Version 1 units can be identified in two ways, the lower PCA assembly has two separate PCA’s
mounted on it and the serial number will indicate the unit was manufactured prior to July
2, 2001.

To replace the lower PCA on a version 1 9.55 treadmills, order (1) 59036-101 9.55 lower PCA
retrofit kit. The kit comes complete with all necessary parts and installation instructions.

9.55 Treadmill

Page 29

Procedure 6.5 - Replacing the Lower PCA (version 2)

1. Set the treadmill circuit breaker in the “off” position. Remove the AC line cord from the AC
outlet.

2. Note the routing and tie down points of all of the wiring coming into the lower PCA. This
information will be required after the replacement lower PCA has been installed. It is
important to have the cabling correctly routed and tied down.

Diagram 6.6 - Lower PCA Mounting (version 2)

3. Disconnect all of the lower PCA wiring (noted in step 2) from the lower PCA.

4. Remove the left, rear mounting screw, left front mounting screw and two right side mounting
screws.

5. Remove the lower PCA from the treadmill. Fasten the lower PCA with the three screws and
nut removed in step 4.

6. Replace all of the lower PCA wiring removed in step 3 per the notes taken in step 2. If
necessary refer to Wiring Diagram 7.4.

Right side

mounting screws

Left, front

mounting screw

Lower PCA

Left, rear

mounting nut

9.55 Treadmill

Page 1-30 Page 30

7. If the treadmill being serviced operates on 120Vac, the 120Vac jumper must be removed
from the defective lower power PCA and re-installed on the replacement lower power PCA
between the M1 connector and the M6 connector.

Caution

If the treadmill being serviced operates on 240 Vac, the jumper in step 12 must not be
installed. If the jumper is installed and the treadmill is operated on 240 Vac, the lower power

PCA will be operated on double the intended voltage. Damage to the lower power PCA will
result.

8. Set the treadmill circuit breaker in the “on” position and check treadmill operation per
Procedure 3.

9.55 Treadmill

Page 31

Procedure 6.6 - Replacing the Speed Sensor

1. Set the treadmill circuit breaker in the “off” position. Remove the AC line cord from the AC
outlet.

2. Disconnect the plug from the J2 connector on the lower logic PCA.

3. Rotate the flywheel so that the speed sensor is between flywheel lobes.

4. Remove the screws that fastens the speed sensor mounting bracket to the treadmill drive
motor. See Diagram 6.7.

Diagram 6.7 - Speed Sensor Mounting

5. Remove the mounting bracket from the drive motor.

6. Remove the two screws that fasten the speed sensor to the bracket.

7. Mount the replacement speed sensor on the mounting bracket with the screws removed in
step 6.

8. Mount the bracket on the drive motor with the screws removed in step 4.

9. Insert the speed sensor plug into the J2 connector on the lower logic PCA.

10. Slowly rotate the flywheel to ensure that the flywheel lobes do not contact the speed sensor.

Mountin

g

Bracket

Screws

Mounting

Sensor

Screw

9.55 Treadmill

Page 1-32 Page 32

11. Set the treadmill circuit breaker in the “on” position and check treadmill operation per
Procedure 3.

9.55 Treadmill

Page 33

Procedure 6.7 - Replacing Drive Motor

1. Set the treadmill circuit breaker in the “off” position and unplug the treadmill’s line cord from
the AC outlet.

1. Remove the hood.

2. The drive motor and flywheel are balanced as a matched pair. Since the flywheel is
balanced to a specific motor, flywheels should not be removed from one and installed on a
different motor. If the drive motor is replaced, the drive motor and flywheel should be
replaced as a unit.

3. Disconnect the wires from the drive motor cooling fan. Disconnect the speed sensor
connector from the J2 connector on the lower logic PCA. Disconnect the drive motor’s in­line connector located in the drive motor wires.

4. Remove the drive belt tension bolt, see Diagram 4.2. Rotate the drive motor as far as
possible toward the rear of the treadmill.

5. Remove the drive belt from the drive motor pulley.

6. Remove the four bolts that fasten the drive motor onto it’s mounting plate. Remove the drive
motor from the treadmill.

7. Remove the screws that mount the speed sensor and bracket onto the drive motor, see
Diagram 6.7.

8. Mount the speed sensor and bracket on the replacement drive motor using the screws
removed in step 7.

9. Remove the four screws that fasten the drive motor cooling fan onto the drive motor. See
Diagram 6.11.

10. Mount the drive motor cooling fan onto the replacement drive motor with the screws
removed in step 9.

11. Set the drive motor in it’s mounting position. Fasten the drive motor to it’s mounting plate
using the bolts removed in step 6.

12. Set the drive belt in place on the drive motor pulley.

13. Rotate the drive motor forward and replace the drive belt tension bolt removed in step 4.
Tension the drive belt per procedure 4.2.

14. Connect the brown and blue fan wires to the drive motor cooling fan. The blue and brown
wires can be connected to either terminal. Reconnect the drive motor in-line connector.
Reconnect the speed sensor to the J2 connector of the lower logic PCA.

9.55 Treadmill

Page 1-34 Page 34

15. Re-install the hood.

16. Check treadmill operation per Procedure 3.

9.55 Treadmill

Page 35

Procedure 6.8 - Replacing the Circuit Breaker

1. Set the treadmill circuit breaker in the “off” position and unplug the treadmill’s line cord from
the AC outlet.

2. Remove the four screws that fasten the circuit breaker mounting plate to the treadmill. See
Diagram 6.8.

Diagram 6.8 - Circuit Breaker Mounting Panel

3. Disconnect all of the wiring from the circuit breaker.

4. Remove the circuit breaker mounting screws. Remove the circuit breaker from the treadmill.

5. Set the replacement circuit breaker in its mounting position. Fasten the circuit breaker to the
circuit breaker mounting panel using the screws removed in step 4.

6. Connect the wiring to the circuit breaker per Diagram 6.9

Mounting

Screw

9.55 Treadmill

Page 1-36 Page 36

Diagram 6.9 - Circuit Breaker Wiring

7. Set the circuit breaker mounting panel in it’s mounting position. Fasten the circuit breaker
mounting panel to the treadmill using the screws removed in step 2.

8. Check treadmill operation per Section 3.

9.55 Treadmill

Page 37

Procedure 6.9 - Replacing the Line Filter

1. Set the treadmill circuit breaker in the “off” position and unplug the treadmill’s line cord from
the AC outlet.

2. Remove the four screws that fasten the circuit breaker mounting plate to the treadmill. See
Diagram 6.8.

3. Disconnect all of the wiring from the line filter.

4. Remove the screws that fasten the line filter to the circuit breaker mounting panel.

5. Set the replacement line filter in it’s mounting position. Fasten the line filter to the circuit
breaker mounting panel with the screws removed in step 4.

6. Connect the wiring to the line filter per Diagram 6.10.

Diagram 6.10 - Line Filter Wiring

7. Set the circuit breaker mounting panel in it’s mounting position. Fasten the circuit breaker
mounting panel to the treadmill using the screws removed in step 2.

8. Check treadmill operation per Section 3.

9.55 Treadmill

Page 1-38 Page 38

Procedure 6.10 - Replacing the Line Cord

1. Set the treadmill circuit breaker in the “off” position and unplug the treadmill’s line cord from
the AC outlet.

2. Remove the four screws that fasten the circuit breaker mounting plate to the treadmill. See
Diagram 6.8.

3. Remove the nut that fastens the line cord’s ground wire (green wire) to the circuit breaker
mounting plate.

4. Disconnect the line cord’s brown wire from the circuit breaker. Disconnect the line cord’s
blue wire from the line filter (120 Vac units) or from the circuit breaker (240 Vac units).

5. Remove the line cord’s strain relief mounting nut and remove the line cord.

6. Remove the mounting nut from the replacement line cord and feed the line cord through the
circuit breaker mounting plate. Fasten the line cord to the circuit breaker mounting plate with
the nut removed in the previous step.

7. Connect the line cord’s brown wire to the circuit breaker per Diagram 6.9.

8. Connect the line cord’s blue wire to the line filter per Diagram 6.10 (120 Vac units) or to the
circuit breaker per Diagram 6.9 (240 Vac units).

9. Connect the line cord’s ground wire (green wire) to the circuit breaker mounting panel with
the hardware removed in step 3.

10. Check treadmill operation per Section 3.

9.55 Treadmill

Page 39

Procedure 6.11 - Replacing the Drive Motor Cooling Fan

1. Set the treadmill circuit breaker in the “off” position and unplug the treadmill’s line cord from
the AC outlet.

2. Remove the hood.

3. Remove the drive motor per Procedure 6.7, steps 2-8.

4. Remove the four screws that mount the drive motor cooling fan to the drive motor. See
Diagram 6.11

Diagram 6.11 - Drive Motor Cooling Fan Mounting

5. Set the replacement drive motor cooling fan at it’s mounting position on the drive moto r and
fasten it with the hardware removed in step 4.

6. Replace the drive motor per Procedure 6.7, steps 11-15.

7. Check treadmill operation per Procedure 3.

Fan

Mounting

Screw

9.55 Treadmill

Page 1-40 Page 40

Procedure 6.12 - Replacing the Drive Motor Brushes

1. Set the treadmill circuit breaker in the “off” position and unplug the treadmill’s line cord from
the AC outlet.

1. Remove the hood.

2. Remove the drive motor per Procedure 6.7, steps 2-6.

3. Remove the screws that retain the drive motor brush cover. Carefully, remove the heavy
paper cover from the brush access opening.

4. Disconnect the brush wire from the tab on the brush housing. Remove the brush spring by
depressing the tab on the brush spring.

5. Remove the brush from it’s brush holder. See Diagram 6.12.

Diagram 6.12 - Drive Motor Brush

6. Slide the replacement brush into the brush holder. Be sure that the angled edge of the brush
is oriented so that the brush face makes full contact with the motor commutator.

7. Reinstall the brush spring and connect the brush wire to the tab on the brush holder.

8. Replace the heavy paper cover in the brush access opening. Replace the brush cover and
fasten it with the screws removed in step 3.

Brush Wire

Brush

Brush Spring

9.55 Treadmill

Page 41

9. Repeat 3-8 with remaining drive motor brush.

10. Replace the drive motor per Procedure 6.7, steps 11-14.

11. Re-install the hood.

12. Check treadmill operation per Procedure 3.

9.55 Treadmill

Page 1-42 Page 42

Procedure 6.13 - Replacing the PROM

Anti-static kits (part number 20024-101) can be ordered from Precor.

1. The PROM and the associated printed circuit assembly (PCA) are static sensitive. Anti­static devices must be used and all anti-static precautions must be followed during this
procedure.

2. Remove the printed circuit assembly per its associated procedure.

3. Currently we are using two styles of IC software packages. they are a 28 pin dual in line
package (DIP28) and a forty-four pin square package (PLCC44). Each of these packages
should be removed with a proper IC removal tool (see the illustrations below)

4. The IC’s may inserted into their socket by hand by carefully aligning the n otch on the IC with
the notch on the IC socket and carefully pressing the IC into its socket. See the illustrations
below for the alignment notches. Care must be taken that the IC legs on a DIP28 are all
aligned in the socket to prevent the legs from bending when inserted. The PLCC44 IC must
be carefully aligned squarely in its socket or it will not insert. Do not force the IC into its,
socket. If it does not insert easily, remove the it and re-align it in its socket.

DIP28 removal tool

PLCC44 removal tool

Notch

Notch

DIP28

Notch

Notch

PLCC44

9.55 Treadmill

Page 43

Wiring Diagram 7.1 - 9.55 (version 1)

9.55 Treadmill

Page 1-44 Page 44

Block Diagram 7.2 - 9.55 120 Vac (version 1)

Note: Fan sense function removed on units manufactured sfter 9/29/2000

9.55 Treadmill

Page 45

Block Diagram 7.3 - 9.55 240 Vac (version1)

Note: Fan sense function removed on units manufactured sfter 9/29/2000

9.55 Treadmill

Page 1-46 Page 46

Wiring Diagram 7.4 - 9.55 120 Vac (version 2)

9.55 Treadmill

Page 47

Wiring Diagram 7.5 - 9.55 240 Vac (version 2)

9.55 Treadmill

Page 1-48 Page 48

Block Diagram 7.6 - 9.55 120 Vac (version 2)

9.55 Treadmill

Page 49

Block Diagram 7.7 - 9.55 240 Vac (version 2)