Precor C542i User manual

C542i Elliptical Fitness Crosstrainer
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C542i 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.
© 2005 Precor Incorporated
Unauthorized Reproduction and Distribution Prohibited By Law
20039-148

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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,
facing the display enclosure.
General System Information
• The ramp operating system has a battery monitoring system. If the battery voltage falls
below 11 Vdc when ramp movement is initiated or the battery voltage falls below 10 Vdc
after ramp movement has been initiated, ramp movement will be stopped and the message
“NO RAMP LOW VOLTAGE” will be displayed. Ramp motion will not be enabled until such
time as the battery voltage exceeds the above limits.
• The generator performs three functions in the EFX. First, by controlling the amount of
electrical load applied to the generator, the user’s pedalling resistance is controlled.
Second, the generator is used to charge the EFX’s internal battery. Lastly, one of the
generators three phase output windings is monitored to determine when the unit is in use
and when it is idle. This system also determines the stride rate by determining the operating
speed (output frequency) of the monitored generator winding.
Warning and Caution Statements and General Safety Guidelines
Warning statements indicate a particularly dangerous activity. Warning statements you will find in
this manual include:
• If the EFX has been in recent use, the load resistors and load resistor mounting bracket may
be extremely hot.
• Because this is a self powered unit, it will either be necessary to either equip the unit with
the optional external power supply or have an assistant pedal on the unit while voltage
measurements are being taken. Because of the danger of working on the unit while it is in
motion using the optional external power supply is strongly recommended.
• When the unit is used, stairarms are in motion, the generator will operate and produce
potentially hazardous voltages even when the battery is disconnected.
• To remove power from the EFX, the optional external power supply (when equipped) must
be disconnected from the wall outlet and the red (positive) lead must be disconnected from
the battery. Always ensure that the EFX external power supply is unplugged from the wall
outlet and the red (positive) lead is removed from the battery when you inspect or adjust the
EFX, or when you isolate, remove, or replace an EFX component.

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• Removing the covers exposes high voltage components and potentially dangerous
machinery. Exercise extreme caution when you perform maintenance procedures with the
cover(s) removed.
• During service operations you will be very close to moving machinery and voltage bearing
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.
• Exercise caution when touching any wire or electrical component during EFX operation.
• A pinching hazard exists when the unit is operated by turning the crankarms by hand. It is
possible to seriously pinch a finger between the crankarm and stairarm. The stairarms
should be removed before operating the crankarms by hand.
• Caution statements are intended to prevent damage to the EFX as a result of the current
activity. Caution statements included in this manual are listed below:
• When it is necessary to lift or move the EFX, ensure that the EFX has adequate support and
that you use proper lifting techniques.
Safety guidelines you should know and follow include:
• Read the owner’s manual and follow all operating instructions.
• Operate the EFX on a solid, level surface.
• Visually check the EFX 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.
• When operating the EFX, 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, while performing service.
• To prevent electrical shock, keep all electrical components away from water and other
liquids.
• Do not use accessory attachments that are not recommended by the manufacturer-such
attachments might cause injuries.

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General Information
For the latest exploded view, part number and part pricing information, visit the Precor dealer
website at “www.precor.com/connection”.
Tools Required
Multimeter Allen wrench set
Anti-static kit Screwdriver set
4” - 6” gear puller 7/16” allen key, socket wrench mounted
Precor part number 20030-108 belt gauge Straight edge
US and metric end wrench set
US and metric socket wrench set
Torque wrench, 200 in./lbs.
Torque wrench, 200 ft./lbs

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Section Two - Preventive Maintenance
Preventive maintenance measures are either scheduled or unscheduled. Scheduled preventive
maintenance activities are included here so that you are aware of preventive measures
performed on a regular basis.
Regular Preventive Maintenance (Owner)
Cleanliness of the EFX and its operating environment will keep maintenance problems and
service calls to a minimum. Precor recommends that you perform the following preventive
maintenance schedule.
After Each Use
• Unplug the optional external power supply (when equipped) from the AC outlet.
• Wipe down the covers, handlebars, stairarm wheels and stairarm ramps with a damp cloth.
Daily Maintenance
Clean the EFX’s frame, covers, stairarms, stairarm ramps and stairarm wheels using water or a
30:1 solution of Simple Green®and water. Wipe the surface of the electronic console with a
damp sponge or soft cloth. Dry with a clean towel. A 30:1 solution of Simple Green®and water is
the only cleaning solution that has been tested and approved for use on the C542i ramps. Use of
any other cleaner, may cause degradation of the ramp anodizing and void the ramp warranty.
The use of an acid (citric) based cleaner will cause ramp anodizing damage and is not authorized
by Precor.
Weekly Maintenance
• Vacuum underneath the EFX, following these steps:
1. Unplug the optional external power supply (when equipped) from the AC outlet.
2. Place the EFX on its side.
Note:
Place a drop cloth under the EFX to protect the flooring and to ensure that the EFX handrail
is not scratched or damaged.
3. Vacuum the rug or damp mop the floor.
4. Make sure that the floor is dry before returning the EFX to an upright position.

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Quarterly Maintenance
1. Remove the rear covers.
2. Check the step up and input belt alignment and tension as in Procedure 5.2.
3. Replace the rear cover.
On-Site Preventive Maintenance (Service Technician)
When you are called to service a EFX, perform these preventive maintenance activities:
• Perform the software diagnostics. Check LED and keypad function. Record the odometer
reading.
• Check speed sensor function (is the stride rate displayed when the unit is in operation?). If
not, see Procedure 6.4.
• Visually inspect the drive belts for cracks, fraying or excessive wear.
• When furnished, inspect the optional power supply cords. If a power supply cord is
damaged, install a new power supply.
• Visually examine all wires and check connectors and wire connections. Secure connections
and replace wiring as necessary.

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Procedure 3.1 - Software Access Codes
The C542i uses the standard access codes to provide access to the various software features. In
using the standardized access codes the keys are hypothetically numbered left to right with key
#1 on the far left and key #7 on the far right. The standard access codes use all sequential key
presses. The allowable delay between key presses is short. If too much time is taken between
key presses the access procedure will be aborted. If the access is aborted, it will be necessary to
start over from the beginning. See Diagram 3.1.
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
Diagram 3.1 - Display Panel
Key 1 Key 7

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Procedure 3.2 - Accessing the Diagnostic Program
The EFX diagnostic software cycles through the following tests:
• Display Test
• Keyboard Test
• Heart Rate Test
• Battery Test
•RPMTest
• Lift Test
• Brake Test
Procedure
1. Start pedalling and continue to pedal as you perform step 2.
2. With the PRECOR banner scrolling, press keys RESET,5,1,7,6,5,7,6,1., sequentially.
3. The message HARDWARE VALIDATION will be displayed for a few seconds.
4. The message DISPLAY TEST will be displayed followed by every LED on the display being
illuminated. Check each LED segment to ensure that all of the segments are illuminated.
Press the ENTER key to advance to the keyboard test.
5. The message KEYBOARD TEST will be displayed followed by a graphical representation of
each key position on the display housing. As each key on the display is pressed the key
representation is turned “off”, indicating that the key is functioning. Check each key in this
manner, including the numeric keyboard. Press and hold the ENTER key for 2 seconds to
advance to the heart rate test.
6. The message HEART RATE TEST will be displayed followed by the unfiltered (U), filtered
(F) and polar (P) heart rate readings if the heart rate option is installed in the EFX and a
chest strap transmitter or a test transmitter is being used. If the heart rate option is not
installed in the EFX the message NO HEART RATE RECEIVER will be displayed instead of
the heart rate readings. Press the ENTER key to advance to the brake test.
7. The message BATTERY TEST will be displayed followed by the battery voltage. Press the
ENTER key to advance to the RPM test.
8. The message RPM TEST will be displayed followed by the pulse (power bit) reading and the
RPM reading. Press the ENTER key to advance to the lift test.
9. The message LIFT TEST will be displayed followed by the ramp level and A/D (analog to
digital) reading. The A/D is the number the system use to track the lift position. The A/D
number will be used in the lift calibration portion of this service manual. (Procedure 5.3).

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10. The message BRAKE TEST will be displayed followed the resistance level and brake level
readings. This test allows you to test the brake (resistance) at each resistance level. Press
the ENTER key to exit the diagnostics program.

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Procedure 3.3 - Displaying the Odometer
Procedure
1. Start pedalling and continue to pedal as you perform step 2.
2. With the PRECOR banner scrolling, press keys RESET,6,5, sequentially.
3. The message INFORMATION DISPLAY will be displayed for a few seconds.
4. The message ODOMETER will be displayed followed by the total number of strides
accumulated. The total number of strides can be converted to miles by dividing by 2241 or
to kilometers by dividing by 1392.5. Press the ENTER key to advance to total strides.
5. The message TOTAL STRIDES will be displayed followed by the total number of strides
logged on the EFX. Press the ENTER key to advance to hour meter.
6. The message HOUR METER will be displayed followed by the total number of hours that
the EFX has been in use. Press the ENTER key to advance to software version.
7. The message SOFTWARE VERSION will be displayed followed by the software versions of
the upper and lower PCA’s. For example, UPPER 1.01 LOWER 1.01. Press the ENTER key
to advance to error log.
8. The message ERROR LOG will be displayed followed by the error in log position 1. Each
log entry shows the log position, the stride count when the error occurred and the hour
meter when the error occurred. For example; 1 ER21 123456 STR 45678 HRS. The error
log can record up to ten error conditions. The error code in position one will be the most
recent error and the error in position ten will be the oldest error. If more than ten errors have
been logged, only the ten most recent will be displayed. When a new error is logged, each
existing error is pushed down one position and the error in position 10, if any, is lost. Use the
 and keys to move through the log. Pressing and holding the QUICK START key for
four seconds will clear the log. Press the ENTER key to exit the odometer program.

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Procedure 3.4 - Club Settings
1. Start pedalling and continue to pedal as you perform step 2.
2. With the PRECOR banner scrolling, press keys RESET,5,6,5,1,5,6,5, sequentially.
3. The message SET CLUB PARAMETERS will be displayed for a few seconds.
4. The message SELECT LANGUAGE will be displayed followed by the currently selected
language. Use the  and  keys to select the language preference. Press the ENTER
key to advance to units of measurement.
5. The message SELECT UNITS will be displayed followed by the currently selected unit of
measurement. Use the  and  keys to select either U.S. Standard or METRIC
measurements. Press the ENTER key to advance to maximum workout time.
6. The message SET MAX WORKOUT TIME will be displayed followed by the currently
selected maximum workout time. Use the  and  keys to select the maximum workout
time. The maximum workout time may be set between 1 and 240 minutes or no limit. Press
ENTER to advance to maximum pause time.
7. The message SET MAX PAUSE TIME will be displayed followed by the currently selected
maximum pause time. Use the  and  keys to select the maximum pause time. The
maximum pause time is the that will elapse after the pause key has been pressed until the
unit resets. The maximum pause time may be set between 1 and 120 seconds. Press
ENTER to exit the club settings program.

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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 mounted on the upper PCA. A label on the PROM indicates the software
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 Operation
This section provides you with a quick method of checking EFX operation. Check the operation
of the EFX at the end of most maintenance procedures.
Procedure
1. Start striding on the EFX or plug the optional external power supply (when available) into the
EFX and the AC outlet.
2. At the PRECOR banner, press QUICK START.
3. Select Resistance Level 1 and press ENTER.
4. Operate the EFX for 4–5 minutes. As you operate the EFX, concentrate on the operating
sounds made by the unit. Be on the alert for unusual rubbing, hitting, grinding, or squeaking
noises.
5. If the EFX makes unusual noises or the electronic display does not change appropriately,
troubleshoot per Section 6.
6. Press the RESISTANCE key until you reach Resistance Level 10. Operate the EFX for
another 2–3 minutes.
7. If the EFX resistance does not change or the operation of the EFX feels inconsistent
compared with Resistance Level 1, troubleshoot per Section 6.
8. Press the RESISTANCE key until you reach Resistance Level 20. Operate the EFX for
another 2–3 minutes.
9. If the resistance of the EFX does not change or the EFX operation feels inconsistent with
Resistance Levels 1 and 10, troubleshoot per Section 6.
10. Check the LED’s mounted on the upper PCA and the function keys displayed on the
electronic console by performing Procedure 3.2.
11. Press the CROSSRAMP key while viewing the electronic console. Confirm that the foot
pads incline and the ramp display increments to 20 as the CROSSRAMP key is pressed.
12. Press the CROSSRAMP key while viewing the electronic console. Confirm that the foot
pads return to a level position and the ramp display decrements to 1 as the CROSSRAMP
key is pressed.
13. If the ramp system of the EFX does not operate properly, troubleshoot per Section 6.

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Procedure 5.1 - Measuring the Resistance of a Generator
Caution
Remove power from the EFX before you measure magnet resistance.
Procedure
1. Remove the rear cover and disconnect the red battery lead from terminal M6 of the lower
PCA.
WARNING
Before continuing with this procedure, review the Warning and Caution statements listed in
Section One, Things You Should Know.
2. Set the ohmmeter to a range that will conveniently read up to 50 Ω.
3. Remove the six phase generator connector from the lower PCA, refer to Diagram 5.1,
below.
4. With an ohmmeter, read between terminals 1 & 2, terminals 1 & 3, terminals 1 & 5, terminals
1 & 6, and terminals 1 & 7 on the six phase generator connector (J1). Each of the six
readings should be between 36 Ω and 39 Ω.
5. If any of the readings are significantly high or significantly low, remove the intermediate
cable from the generator and perform the same measurements as in step 4 on the
generator connector. If the reading are now correct check and or replace the intermediate
cable. If the readings are still incorrect, remove the six phase generator.
Diagram 5.1 - Lower PCA
Prom
Data Cable
Battery
AC Adapter
Load
Six Phase
Generator

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6. Replace the generator per procedure 7.17. Reconnect the intermediate cable removed in
step 5 to the replacement generator and the lower PCA.
7. Reconnect the red battery lead to terminal M6 of the lower PCA.

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Procedure 5.2 - Inspecting and Adjusting Belt Tension
Procedure
1. Remove the rear cover and disconnect the red battery lead from terminal M6 of the lower
PCA. If you are only inspecting the generator belt tension, skip to step 7.
WARNING
Before continuing with this procedure, review the Warning and Caution statements listed in
Section One, Things You Should Know.
.
WARNING
If the EFX has been in recent use, the load resistors and mounting bracket may be extremely
hot.
2. Remove the three screws that fasten the load resistor assembly and shield to the frame
upright. Rotate the load resistor assembly 180 degrees and set it on the top of the frame
upright.
3. Place a 20030-108 or equivalent belt gauge on the input belt as shown in Diagram 5.2.
Diagram 5.2 - Input Belt Tension Measurement
4. The belt gauge should read 100 lbs. If the belt tension is significantly high or low the belt
tension may be adjusted using the adjustment bolts shown in Diagram 5.2. To adjust the
belt tension first straighten the locking tabs on both bolts. When adjusting the tension, turn
Adjustment
Bolt
Belt Gauge
Step Up
Pulley

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both bolts equal amounts. When the adjustment is complete the step up pulley shaft must
remain perpendicular to the frame and drive belt. Turning the adjustment bolts clockwise will
increase belt tension, turning the adjustment bolts counter-clockwise will decrease belt
tension.
5. Changing the tension of the input drive belt will also affect the tension of the generator belt.
If the input belt tension has been changed, continue with step 7.
6. Place a 20030-108 or equivalent belt gauge on the generator belt as shown in Diagram 5.3.
Diagram 5.3 - Generator Belt Tension Measurement
7. The belt gauge should read 60 lbs. If the generator belt tension is significantly high or low, it
may be adjusted using the adjustment bolt shown in Diagram 5.2. First loosen, but do not
remove the four generator mounting bolts and the jam nut. Hold the adjustment bolt head
with one wrench and turn the adjustment nut to change the belt tension. When the tension is
correct, tighten the jam nut. Tighten and torque the four generator mounting bolts to 150
inch pounds.
8. If either the input pulley belt or the generator belt is being replaced with a new belt, the belt
tension should be set 20 lbs. higher than the previous readings. Therefore a new input
pulley belt should be tensioned to 120 lbs. and a new generator belt should be tensioned to
80 lbs. Over time and use the belts will “relax” and the tensions will be as stated in steps 4
and 7.
9. Reconnect the red battery lead to terminal M6 of the lower PCA.
Adjustment
Bolt Generator
Mounting
Bolt
Jam Nut
Adjustment Nut

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Procedure 5.3 - Calibrating the Lift Motor
1. Remove both front covers.
2. Remove the four screws that fasten the lift motor yoke into the ramp.
3. Carefully, slide the lift motor yoke out of the ramp and lower the ramp until it is resting on the
frame.
Diagram 5.4 - Lift Motor Mounting and Calibration
4. Access the lift A/D reading via the Lift Test portion of the Diagnostic Program, see
Procedure 3.2.
5. With the A/D number displayed set it for a reading of 127 using the CROSSRAMP and
CROSSRAMP keys.
6. Rotate the lift yoke on the lift motor drive screw until the measurement between the top of
the lift nut and the end of the lift motor drive screw is 9 inches. See Diagram 5.4. While
rotating the lift motor yoke, do not allow the lift motor drive screw to rotate. If the lift motor
drive screw rotates, the A/D number will change. The A/D number must be 127 and the
physical measurement must be 9 inches for the calibration to be correct.
7. Lift the ramp off of the frame and slide the lift motor yoke into the ramp. Do not rotate the lift
any more than is absolutely necessary to align the lift motor yoke with the ramp.
8. Apply a light coating of blue loctite to the four screws removed in step 2. Fasten the lift motor
yoke with the loctited screws and torque them to 240 inch pounds.
9”
Lift Yoke

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Procedure 6.1 - Troubleshooting the Lower and Upper
Interconnect Cable
Typical symptoms associated with a defective interconnect cable is either an error 30 or no
power to the upper PCA. This procedure requires that you have a known good upper
interconnect cable, lower interconnect cable and mid-point connector
.
9. If you are troubleshooting an error 30, 31 or 32 continue with step 3, otherwise see
Procedure 6.3.
10. Pry the end cap out of the front of the frame base tube (See Diagram 6.1).
11. Carefully withdraw both cables and mid-point connector.
Diagram 6.1 - Interconnect Cables and Mid-Point Connector
12. Disconnect both cables from the mid-point connector and replace the mid-point connector
with a known good mid-point connector. If the mid-point connector does not correct the
problem, replace the original mid-point connector and continue with step 5.
Lower
Interconnect
Cable
Mid-point
Connector
End Cap
Upper
Interconnect
Cable

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13. Remove the rear cover. Disconnect the lower interconnect cable from the lower PCA and
the mid-point connector. Substitute a known good interconnect cable from the lower PCA to
the mid-point connector. It is not necessary to route the test interconnect cable through the
frame tube, for convenience route it externally.
14. If the lower interconnect cable corrects the problem, replace the cable per Procedure 7.3. If
the lower interconnect cable does not correct the problem, re-connect the original lower
interconnect cable to the lower PCA and mid-point connector and continue with step 7.
15. Remove the upper display housing per Procedure 7.1, steps 1 to 4. Disconnect the upper
interconnect cable from the mid-point connector. Substitute a known good interconnect
cable from the upper PCA to the mid-point connector. It is not necessary to route the test
interconnect cable through the frame tube, for convenience route it externally.
16. If the upper interconnect cable corrects the problem, replace the cable per Procedure 7.3. If
the upper interconnect cable does not correct the problem, re-connect the original upper
interconnect cable to the mid-point connector and continue with step 9.
17. Replace the upper PCA per Procedure 7.1, steps 9 to 11.
18. If you have performed all of the procedures above and have been unable to correct the
problem, call Precor customer service.