Precor C544 User manual

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C544 Elliptical Fitness Crosstrainer
Warning: This service manual is for use by Precor trained service providers only.
IfyouarenotaPrecorTrainedServicer,youmustnotattempttoserviceanyPrecorProduct;
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

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Section One - Things You Should Know
Right, Left, Front, and Back Conventions
In this manual, right, left, front, and back are from the perspective of a user standing on the EFX
544, facing the display enclosure.
Warning and Caution Statements and General Safety Guidelines
Warning statements indicate a particularly dangerous activity. Warning statements you will find in
this manual include:
• To remove power from the EFX 544, the power cord must be disconnected from the wall
outlet. Always ensure that the EFX 544 is unplugged from the wall outlet when you inspect
or adjust the EFX 544, or when you isolate, remove, or replace an EFX 544 component.
• Removing the covers exposes high voltage components and potentially dangerous
machinery. Exercise extreme caution when you perform maintenance procedures with the
hood removed.
• During service operations you will be very close to moving machinery and high voltage
components. When you perform maintenance procedures with the covers removed, remove
jewelry (especially from ears and neck), tie up long hair, remove neck ties, and do not wear
loose clothing.
• When the EFX 544 is operating, the capacitor will hold a lethal amount of charge. Do not
touch the capacitor as serious injury or death might result.
• When the EFX 544 is turned off and the power cord is removed from the wall outlet, the
capacitor will hold voltage for 30–60 seconds. Allow the capacitor to discharge for a period
of one minute before you touch or work near the capacitor. Do not attempt to discharge the
capacitor by any other means.
• Exercise caution when touching any wire or electrical component during EFX 544 operation.
• Exercise extreme caution when working with the flywheels and/or the stairarms. Because of
the mass of the flywheels, serious injury may result if fingers are pinched between the
flywheel spokes and the stairarms.
• The flywheel is very heavy. Be prepared for the weight of the flywheel when it comes off of
the pulley shaft.
Caution statements are intended to prevent damage to the EFX 544 as a result of the current
activity. Caution statements included in this manual are listed below:
• Notice the orientation notch on the PROM (U3). These components must be positioned with
the same notch orientation.

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• When it is necessary to lift the EFX 544, ensure that the EFX 544 has adequate support. Do
not lift the EFX 544 by the front cross-member.
Safety guidelines you should know and follow include:
• Read the owner’s manual and follow all operating instructions.
• Operate the EFX 544 on a solid, level surface. Locate the rear of the EFX 544 at least four
feet from walls or furniture. Keep the area behind the EFX 544 clear.
• Visually check the EFX 544 before beginning service or maintenance operations. If it is not
completely assembled or is damaged in any way, exercise extreme caution while operating
and checking the EFX 544.
• When operating the EFX 544, do not wear loose clothing. Do not wear shoes with heels or
leather soles. Check the soles of your shoes and remove any embedded stones. Tie long
hair back.
• Do not rock the unit. Do not stand or climb on the handlebars, display enclosure, or cover.
• Do not set anything on the handlebars, display enclosure, or cover. Never place liquids on
any part of the EFX 544.
• To prevent electrical shock, keep all electrical components, such as the power cord and
circuit breaker away from water and other liquids.
• Do not use accessory attachments that are not recommended by the manufacturer-such
attachments might cause injuries.
General Information
For the latest exploded view, part number and part pricing information, visit the Precor dealer
website at “www.precor.com/Dealer”.

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Procedure 3.1 - Software Access Codes
Over the years the codes used to access the various software diagnostics features have
changed. Currently we are using a “standardized” set of access codes. These codes will be used
on all current and future software. In using the standardized access codes the keys are
numbered left to right with key #1 on the far left and key #7 on the far right. If the standard access
codes do not function on the unit being tested refer to the appropriate old access codes listed
below. The standard access codes use all sequential key presses, the old access codes use
simultaneous key presses.
Standard Access Codes
Diagnostics Keys RESET,5,1,7,6,5,7,6,1
Odometer Keys RESET,6,5
Club Settings Keys RESET,5,6,5,1,5,6,5
Old Access Codes
Diagnostics Keys Ramp ▲, Resistance ▼, Resistance ▲
Odometer Keys Ramp ▲, Resistance ▲
Club Settings Keys Resistance ▲, Quick Start/Change

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Procedure 3.2 - Accessing the Diagnostic Software
The EFX 544 diagnostic software cycles through the following tests:
• Performing LED Diagnostics
• Checking the Lift Calibration Number
• Determining Software Version
• Heart Rate Diagnostic
• Performing the Keypad Test
Procedure
1. Plug the power cord into the wall outlet, then turn on the EFX 544 with the circuit breaker.
2. Press the RAMP ▲,RESISTANCE ▼and RESISTANCE ▲ keys, simultaneously or keys
RESET,5,1,7,6,5,7,6,1, sequentially.
3. Watch the upper display as the LED test progresses. The test is programmed to display the
following LED illumination sequence:
a Every LED on the left display window illuminates simultaneously.
b Diagonal lines of illuminated LED’s sweep across the left display window.
c The right display windows illuminate, then decrement from 8.8.8.8 to 0.0.0.0.
d The function LED’s illuminate simultaneously and then extinguish.
e Each function LED illuminates separately and then extinguishes.
4. With LIFT displayed in the right display window, watch the right display window (shown in
Diagram 3-1). Press the RAMP ▲and RAMP ▼keys. Verify that the lift calibration number
increments and decrements as the RAMP keys are pressed.
5. If you do not observe the LED illumination sequences described in Step 3...
THEN... OTHERWISE...
Replace the upper PCA as described The LED passed successfully;
in Procedure 8.2. continue with the next step.

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Diagram 3.1 - C544 Display
6. Press ENTER, then release.
7. Note the software version number displayed in the right middle display window.
Note:
If you cannot determine the software version number in this manner, look at the PROM (U3)
mounted on the upper PCA. A label on U3 indicates the software version number. The part
number of the PROM indicates the version number.
8. Press ENTER, then release.
9. With HArt displayed in the right display window, a heart rate will be displayed when a chest
strap or test transmitter is used.
10. Press ENTER until seven dots illuminate in the left display window.
11. Press each key listed below. Verify that each single dot expands to four dots as the
appropriate key is pressed.
ENTER Expands the far left dot.
RAMP DOWN Expands the second dot from the left.
RAMP UP Expands the third dot from the left.
STOP/RESET Expands the center dot.
RESISTANCE DOWN Expands the third dot from the right.
RESISTANCE UP Expands the second dot from the right.
QUICK START Expands the far right dot.

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12. If the left display window column illuminates appropriately as each key is pressed...
THEN... OTHERWISE...
The keypad test passed successfully; Replace the upper PCA as described
continue with the next step. in Procedure 8.2.
13. End the keypad test by pressing the RAMP ▼and RESISTANCE ▲keys, simultaneously.

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Procedure 3.3 - Displaying the Odometer
Procedure
1. Plug the power cord into the wall outlet, then turn on the EFX 544 with the circuit breaker.
2. With the PRECOR EFX 544 banner scrolling, press the RAMP ▲and RESISTANCE ▲
keys, simultaneously or keys RESET,6,5, sequentially. The messageEFX 544 ODOMETER
will scroll across the left display window.
3. Press ENTER, then release.
Note:
The right display window displays the total strides on the EFX 544 (see Diagram 3.2). The
number displayed is 102,187. To convert strides to miles, divide the total number of strides by
2241. To convert strides to kilometers, divide the total number of strides by 1392.5.
Diagram 3-2. - Odometer Reading
8712 10

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Procedure 3.4 - Club Settings
Selecting United States standard units causes information to be displayed in miles. Information is
displayed in kilometers if metric units are selected. After you select a measurement standard, the
software accumulates and records workout information in the units of the measurement standard
selected.
Procedure
1. Plug the power cord into the wall outlet, then turn on the EFX 544 with the circuit breaker.
2. With the PRECOR EFX 544 banner scrolling, press the RESISTANCE ▲and QUICK
START keys simultaneously or keys RESET,5,6,5,1,5,6,5, sequentially. Either U. S.
Standard or Metric will scroll across the display.
3. If you wish to change the measurement standard...
THEN... OTHERWISE...
Use the ▲or ▼keys to toggle Continue with the next step.
to an alternate measurement standard;
then continue with the next step.
4. Press ENTER, then release.
5. Either 120 VOLTS or 240 VOLTS will scroll across the display. Press either of the ▲ or ▼
keys to toggle between the 120 0r 240 volt setting.
Note:
The 120 Volt/240 Volt setting does not change the input operating voltage of the EFX 544. It
changes the resistance levels to match the input operating voltage. Therefore, this setting must
match the input voltage of the EFX 544. If the setting does not match the input voltage, the
resistance levels will be incorrect.
6. The maximum workout time is displayed on the left display window.
7. If you wish to change the maximum workout time...
THEN... OTHERWISE...
Use the ▲or ▼keys to select Press ENTER to continue with the next step.
the new maximum workout time;
then continue with the next step.
8. Either SMART RATE ACTIVATED or NO SMART RATE will scroll across the display. Use
the ▲ or ▼ keys to activate or deactivate smart rate, as required. Press ENTER to exit.

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Procedure 3.5 - Documenting Software Problems
When a problem is found with either the software or upper or lower PCA’s, record the information
listed below. If you isolated the problem to either the PROM, upper PCA, or lower PCA, include
the information you recorded with the malfunctioning PROM or PCA when you ship it to Precor.
When a problem occurs, record the following information:
• Model and serial number
• Software version number
Note:
Look at the PROM (U3) mounted on the upper PCA. A label on U3 indicates the software version
number. The part number of the PROM indicates the version number.
• User and 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 Four - Checking EFX 544 Operation
This section provides you with a quick method of checking EFX 544 operation. Check the
operation of the EFX 544 at the end of most maintenance procedures.
Procedure
1. Plug the power cord into the wall outlet, then turn on the EFX 544 with the circuit breaker.
2. When the PRESS ENTER FOR PROGRAMS prompt appears, press QUICK START.
3. If the ramp is not currently at the mid-point, the ramp will automatically move to the mid-
point.
4. Select Resistance Level 1 and press ENTER.
5. Operate the EFX 544 for 4–5 minutes. As you operate the EFX 544, concentrate on the
operating sounds made by the unit. Be on the alert for unusual rubbing, hitting, grinding, or
squeaking noises.
6. If the EFX 544 makes unusual noises or the electronic display does not change
appropriately, trouble shoot per section 6.
7. Press the RESISTANCE ▲ key until you reach Resistance Level 5. Operate the EFX 544
for another 2–3 minutes.
8. If the EFX 544 resistance does not change or the operation of the EFX 544 feels
inconsistent compared with Resistance Level 1, troubleshoot per section 6.
9. Press the RESISTANCE ▲ key until you reach Resistance Level 10. Operate the EFX 544
for another 2–3 minutes.
10. If the resistance of the EFX 544 does not change or the EFX 544 operation feels
inconsistent with Resistance Levels 1 and 5, troubleshoot per section 6.
11. Check the LED’s mounted on the upper PCA and the function keys displayed on the
electronic console by performing Procedure 3.2.
12. Press the RAMP ▲key while viewing the electronic console. Confirm that the foot pads
incline and the ramp display increments to ten as the RAMP ▲key is pressed.
13. Press the RAMP ▼ key while viewing the electronic console. Confirm that the foot pads
return to a level position and the ramp display decrements to zero as the RAMP ▼key is
pressed.
14. Turn off the EFX 544 with the circuit breaker, then unplug the power cord from the wall
outlet.

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Procedure 5.1 - Inspecting and Adjusting the Gap Between
the Disk and Magnet Assembly
Note:
This procedure is applicable only to units manufactured prior to March 20, 1997
Procedure
1. Turn off the EFX 544 with the circuit breaker, then unplug the power cord from the wall
outlet.
WARNING
Before continuing with this procedure, review the Warning and Caution statements listed in
Section One, Things You Should Know.
2. Remove the rear cover as described in Procedure 7.1.
3. Place a. 062" (1/16”) feeler gauge between the disk and the magnets (see Diagram 5.1).
4. If the feeler gauge does not fit snugly...
THEN... OTHERWISE...
Continue with the next step. Skip to Step 9.
Diagram 5.1 - The Magnets and Disk

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5. Loosen the two screws that secure the magnet assembly to the magnet pivot assembly.
IMPORTANT
Do not loosen the screws too much. Although you must be able to move the magnet assembly
along the adjustment slots, the assembly must stay in place after it is moved.
6. Place a .062" (1/16”) feeler gauge between the disk and the magnets.
7. Slide the magnet assembly along its adjustment slots until the feeler gauge fits snugly
between the disk and the magnets.
8. Using the 6 mm allen wrench, tighten the screws that secure the magnet assembly to the
magnet pivot assembly.
9. Re-install the rear cover as described in Procedure 7.1, then check the operation of the EFX
544 as described in Section Four.

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Procedure 5.2 - Measuring the Resistance of a Magnet
Caution
Remove power from the EFX 544 before you measure magnet resistance.
Procedure
1. Turn off the EFX 544 with the circuit breaker, then unplug the power cord from the wall
outlet.
WARNING
Before continuing with this procedure, review the Warning and Caution statements listed in
Section One, Things You Should Know.
1. Remove the rear cover as described in Procedure 7.1.
2. Set the ohmmeter to a range that will conveniently read 125 Ω.
3. Remove the wires from the terminals on the top magnet. Measure the resistance between
the two terminals.
Note:
The resistance of the magnets will be higher than optimum (90 - 110 Ω) when they are warm.
4. If the resistance measures significantly less than 90 Ωor significantly more than 110 Ω...
THEN... OTHERWISE...
Replace the magnet as described Connect the wires to the magnet, then
in Procedure 7.19. continue with the next step.
Note:
The EFX 544 magnet cable assembly is shown in Diagram 5-2.
5. Repeat Steps 4 and 5 for the remaining magnets.
6. Re-install the rear cover as described in Procedure 7.1, then check the operation of the EFX
544 as described in Section Four.

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Diagram 5.2 - Magnet Wiring

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Procedure 5.3 - Calibrating the Lift Motor
Note:
The lift motor must be removed for calibration.
Removing the Lift Motor Assembly
1. Set the ramp (lift) at level 1, turn off the EFX 544 with the circuit breaker, then unplug the
power cord from the wall outlet.
2. Remove the front and rear covers as described in Procedure 7.1.
Note:
Refer to the wiring diagram shown in Diagram 8.1. Mark all wires before disconnecting, to insure
quick, accurate replacement!
3. Lift the stair arms from the ramp assembly and rotate them towards the back of the EFX
544.
4. Rotate the ramps to the back of the unit. Rest the ramps on the flywheels.
5. Remove the outboard snap rings from each end of the lower lift shaft. Remove the plastic
wear tubes. Hold one end of the lower lift shaft with a wrench. Loosen the other end with a
second wrench. Using the wrenches, unthread both ends of the lower lift shaft from the
threaded stud. Set aside the lower lift shaft and the stud.
Note:
Units built before September 3, 1996, may have a one-piece lower lift shaft.
6. Cut the cable ties that secure the ribbon cable to the lift motor and EFX 544 wiring cables.
7. Disconnect the lift motor cable assembly from the lower PCA.
8. Remove the wires from the lift motor capacitor.
9. Remove the screw that secures the lift motor ground wire to the EFX 544 frame.
10. Remove the two screws securing the top of the electronics bracket to the EFX 544 frame.
11. While an assistant supports the lift motor, remove the nut from upper lift motor mounting
bolt. Remove the upper lift motor mounting bolt and the two plastic spacers (read the Note
below).
Note:
Units built after July 9, 1996, have two plastic spacers inserted onto the upper lift shaft.
12. Lift the lift motor assembly up and away from the EFX 544 (see Diagram 5.3).

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Calibrating the Lift Motor Assembly
13. Position the lift motor assembly on the floor, close to the EFX 544 frame.
Diagram 5.3 - Lift Motor Assembly

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14. Refer to Diagram 8.1. Re-connect the lift motor cables to the lower PCA and lift capacitor.
Connect the lift motor ground wire.
15. Plug the power cord into the power entry module, then plug the power cord into the wall
outlet. Turn on the circuit breaker.
16. Access the EFX 544 diagnostic program by pressing Ramp ▲, Resistance ▼and
Resistance ▲simultaneously or keys 4,5,1,7,6,5,7,6,1.
17. When the LED test is complete and the EFX 544 is in lift calibration mode, operate the
Ramp ▲or Ramp ▼keys until 12 is shown on the display.
18. Exit the diagnostic program.
19. With the Precor banner scrolling, turn off the EFX 544 with the circuit breaker. Unplug the
power cord from the wall outlet.
20. Without allowing the lead screw to turn, thread the lift tube clockwise until it reaches the top
of the lead screw. Again without allowing the lead screw to turn, thread the lift tube
counterclockwise three and a half turns.
21. Disconnect the lift motor cable from the lower PCA, and lift capacitor.
22. Remove the screw that secures the lift motor ground wire to the EFX 544 frame.
Replacing the Lift Motor Assembly
23. Remount the upper end of the lift motor with the nut and bolt removed in step 11.
24. Position the lift motor assembly against the lift guide. Align the bore in the lift tube with the
bore in the lift bracket.
25. Remove the lower lift shaft from the threaded stud. Clean off the old loctite. Put a small
amount of blue loctite on the threaded stud. Thread one end of the lower lift shaft onto the
stud, then insert the shaft with the stud through the lift guide clamp.
26. Thread the remaining lower lift shaft onto the stud. Hand tighten the lower lift shaft and then
use the two wrenches to tighten it an additional 1/4 turn.
27. Slide both wear tubes onto the lower lift shaft and replace the snap rings on each end of the
lower lift shaft (see Diagram 5.4).

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Diagram 5.4 - Exploded View of the Lift System
28. Insert the upper lift shaft through the EFX 544 frame and upper lift motor assembly. Replace
the plastic spacers (if you have a unit built after June 19, 1996) and the snap ring on the end
of the upper lift shaft.
29. Position the lower electronics bracket against the EFX 544 frame. Replace the two screws
that secure the top of the bracket to the frame.
30. Refer to Diagram 7-3. Re-connect the lift motor cables to the lower PCA and lift capacitor.
Connect the lift motor ground wire.
31. Replace the screw that secures the lift motor and EFX 544 ground wires to the frame.
32. Using a large cable tie, secure the ribbon cable, lift motor cable and lift motor capacitor
wires to the lift motor. Loop the lift motor cable over the lift motor until the lift motor cable lies
flat against the motor casing.
33. Rotate the ramps and then the stair arms to the front of the EFX 544. Position the stair arms
on the ramp.
34. Re-install both covers.

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Procedure 6.1 - Troubleshooting the Ribbon Cable
1. With the lift set at level 1, turn off the EFX 544 with the circuit breaker.
WARNING
Before continuing with this procedure, review the Warning and Caution statements listed in
Section One.
2. Remove the front cover.
3. Attach the wrist strap to your arm, then connect the ground lead of the wrist strap to the EFX
544 frame.
4. Disconnect the ribbon cable from the lower PCA.
5. Remove the screws that secure the upper display module assembly to the upper frame
member.
CAUTION
When you perform the next step, tape the ribbon cable to the EFX 544 to prevent it from falling
into the upper frame member.
6. Disconnect the ribbon cable from the upper PCA. Set aside the upper display module.
7. Connect the spare ribbon cable between the upper PCA and the lower PCA.
8. Check the operation of the EFX 544 as described in Section Four.
9. If the EFX 544 operates correctly with the spare ribbon cable...
THEN... OTHERWISE...
Install a new ribbon cable on the Continue with the next step.
EFX 544 as described in Procedure 7.5.
10. Turn off the EFX 544 with the circuit breaker.
11. Disconnect the spare ribbon cable from the upper and lower PCA’s.
12. Connect the original ribbon cable to the upper and lower PCA’s.