Precor 5.21i User manual

5.21i Elliptical Fitness Crosstrainer
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5.21i 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.
© 2004 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
5.21i, 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 5.21i, the power cord must be disconnected from the wall
outlet. Always ensure that the EFX 5.21i is unplugged from the wall outlet when you inspect
or adjust the EFX 5.21i, or when you isolate, remove, or replace a EFX 5.21i 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.
• Exercise caution when touching any wire or electrical component during EFX 5.21i
operation.
Caution statements are intended to prevent damage to the EFX 5.21i as a result of the current
activity. Caution statements included in this manual are listed below:
• Notice the orientation notch on the PROM. These components must be positioned with the
same notch orientation.
Safety guidelines you should know and follow include:
• Read the owner’s manual and follow all operating instructions.
• Visually check the EFX 5.21i 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 5.21i.
• When operating the EFX 5.21i, 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.

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• Do not set anything on the handlebars, display enclosure, or cover. Never place liquids on
any part of the EFX 5.21i other than a water bottle in the water bottle holder during normal
operation.
• 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/connection.

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Required Tools and Equipment
The following list is a summary of the tools and equipment required when you service Precor’s
EFX 5.21i.
TOOLS EQUIPMENT
phillips and flat-head screwdrivers anti-static wrist strap (20024-101)
digital multimeter
standard and metric allen wrench sets
open-end wrench set Supplies
blue loctite
drive ratchet and ratchet set
socket drive allen set cable ties
chip puller Spares
rubber mallet interconnect cables
snap ring pliers
100 ft./lb. torque wrench
300 in./lb. torque wrench
belt gauge (part # 20030-117)

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Procedure 2.1 - Accessing the Diagnostic Program
The EFX 5.21i diagnostic software cycles through the following tests:
• Display Test
• Keyboard Test
• Heart Rate Test
• Lift A/D Test
• Brake (eddy current) Test
Procedure
1. Plug the power cord into the wall outlet, then turn on the EFX 5.21i with the on/off switch.
Note:
For the purpose of entering the key sequences to access the various diagnostic programs, the
keypad keys are hypothetically numbered from 1 to 7 from left to right.
2. With the PRECOR EFX 5.21i banner displayed, access the diagnostic program by pressing,
keys RESET,5,1,7,6,5,7,6,1, sequentially.
Diagram 2.1 - 5.21i Display

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3. Watch the display as the LED test progresses. The test is programmed to display the
following LED illumination sequence:
a. The test name “DISPLAY TEST” will be scrolled.
b. All of the L.E.D.s on the display will be illuminated.
3. Press the RESET key to proceed to the keyboard test.
4. The test name “KEYBOARD TEST” will be scrolled.
5. A graphical representation of all the keys on the keyboard will be displayed. When a key is
pressed the representation of the key will become a single dot. Check all of the keys on the
keyboard in this manner.
6. Press and hold the RESET key for a minimum of 2 seconds to proceed to the heart rate test.
7. The test name “HEART RATE TEST” will be scrolled.
8. A chest strap heart rate transmitter or a heart rate test transmitter must be used in
conjunction with this test.
9. When a heart rate signal is received, the Polar heart rate will be displayed as “P XXX” and
the SCAN L.E.D. will flash in time with the heart rate.
10. Press the RESET key to proceed to the lift test.
11. The test name “LIFT A/D” will be displayed for 2 seconds.
12. The lift calibration number will be displayed on the right. The lift calibration number indicates
the physical position of the incline and is used to calibrate the lift motor.
13. Press the RESET key to proceed to the brake test.
14. The test name “BRAKE” will be displayed for 2 seconds.
15. The resistance level will be displayed on the left side of the display and the corresponding
power bits (duty cycle) will be displayed on the right side of the display. Initially, the power
bits level will be zero, pressing the , keys will change the number of power bits being
applied to the eddy current system.
16. Press the RESET key to exit the diagnostics program.

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Procedure 2.2 - Accessing the Information Display
Procedure
1. Plug the power cord into the wall outlet, then turn on the EFX 5.21i with the on/off switch.
2. With the PRECOR EFX 5.21i banner displayed, press keys RESET,6,5, sequentially.
The EFX 5.21i Information display cycles through the following displays:
a. Odometer
b. Hour meter
c. Software version
d. Error log
5. The display name “ODOMETER” will be displayed for 2 seconds. Then the odometer value
will be displayed, as total strides accumulated.
6. Press the ENTER key to proceed to the hour meter display.
7. The display name “HOUR METER” will be displayed for 2 seconds. Then the hour meter
value will be displayed, as the total number of hours of use. Fractional parts of an hour are
stored internally, the display will be truncated to the nearest full hour.
8. Press the ENTER key to proceed to the software version display.
9. The display name “SW VERSION” will be displayed for 2 seconds.
10. The upper software version (UPPER X.XX) will be displayed. Pressing either SELECT key
will toggle between the upper and lower software version display.
11. Press the ENTER key to proceed to the error log display
12. The display name “ERROR LOG” will be displayed for 2 seconds.
13. The first error log entry will be displayed (1: ERXX).
14. Pressing the , keys will move you through the log entries. Entry 1 will be the most recent
error log entry, with each succeeding entry being older than the preceding entry.
15. Pressing the SELECT key will toggle the display between the log entry (ERROR), the
odometer reading (STRIDES) when the error occurred and the hour meter (HOURS) when
the error occurred.

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16. Pressing and holding the QUICK START key for 2 seconds will cause the prompt CLEAR?
to be displayed, holding the QUICK START for an additional 2 seconds will clear all existing
entries from the error log. The display will confirm that the error log has been cleared by
displaying OK. The display will revert to the first log entry and show it as a null entry (1: ---).
If the QUICK START key is not held for a minimum of 4 seconds, the error log will not be
cleared.
17. Press the ENTER or RESET key to exit the information display program.

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Procedure 2.3 - Accessing the Set User Parameters Display
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 5.21i with the on/off switch.
2. With the PRECOR EFX 5.21i banner displayed, press keys RESET,5,6,7,1, sequentially.
3. The display name “SELECT UNITS” will be displayed for 2 seconds.
4. One of two measurement standards will be displayed, U. S. Standard or Metric.
5. If U. S. Standard is selected, weights will be in pounds and distances will be in miles. If
Metric is selected, weights will be in kilograms and distances in kilometers.
6. Pressing any arrow key will toggle the units of measure between US Standard and Metric.
7. Press the ENTER key to save the currently displayed selection and exit the set user
parameters display or press the RESET key to leave the selection unchanged and exit the
set user parameters display.

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Procedure 2.4 - 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 have 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 numbers for upper and lower PCA’s
Note:
Look at the PROM mounted on the upper PCA. A label on the PROM 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 Three - Preventive Maintenance
Preventive maintenance measures are either scheduled or unscheduled. Scheduled preventive
maintenance activities are included here so that you are aware of the preventive measures to be
performed on a regular basis.
Regular Preventive Maintenance (Owner)
Cleanliness of the EFX 5.21i and its operating environment will keep maintenance problems and
service calls to a minimum. Precor recommends that you perform the following preventive
maintenance schedule.
At the End of Each Day
Wipe down the stairarms, ramps, wheels and frame with a damp cloth.
Every Week
Wipe the surface of the electronic console with a slightly-damp sponge or soft cloth. Dry with a
clean towel.
CAUTION
Keep water away from electronic components to prevent shock.
On-Site Preventive Maintenance (Service Technician)
Perform the following preventive maintenance tasks each time you are called to service a EFX
5.21i:
Examine the belts for wear, cracks or other signs of deterioration and replace if necessary.
Check the LED’s mounted on the upper PCA and the function keys displayed on the electronic
console by performing Procedure 2.1.
Visually examine all wires and check connectors and wire connections. Secure connections and
replace wiring as necessary.

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Section Four - Checking EFX 5.21i 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. Plug the power cord into the wall outlet and set the on/off switch in the “on” position.
2. With the PRECOR EFX 5.21i banner displayed, press QUICK START.
3. Select Resistance Level 1.
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 5.21i does not change or the EFX operation feels inconsistent
with Resistance Levels 1 and 10, troubleshoot per Procedure 6.5.
10. Check the LED’s mounted on the upper PCA and the function keys displayed on the
electronic console by performing Procedure 2.1.
11. Turn off the EFX with the circuit breaker, then unplug the power cord from the wall outlet.

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Procedure 5.1 - Measuring the Resistance of an Eddy Current
Magnet
Caution
Remove power from the EFX before you measure magnet resistance.
Procedure
1. Set the on/off switch in the “off” position, 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 up to 125 Ω.
3. Disconnect the magnet wires from the magnet using the quick disconnects shown in the
Diagram 5.1 or Diagram 5.2, below. Measure the resistance between the two magnet wires.
Diagram 5.1 - Eddy Current Magnet (serial codes F8 and SS)
Note:
The resistance of the magnets will be higher than optimum (90 - 110 Ω) when they are warm.
Magnet
Wires
Eddy Current
Magnet

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Diagram 5.2 - Eddy Current Magnet (serial code A998)
4. If the resistance measures significantly less than 90 Ωor significantly more than 110 Ω.
THEN... OTHERWISE...
Replace the magnet as described Reconnect the magnet wires, then
in Procedure 7.13. continue with the next step.
5. Re-install the rear cover as described in Procedure 7.1, then check the operation of the unit
as described in Section Four.
6. Set the on/off switch in the “on” position. Thoroughly test all lift related functions per Section
Four.
7. Set the on/off switch in the “off” position, replace the front cover per Procedure 7.1.
Eddy Current
Magnet
Magnet
Cable

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Procedure 5.2 - Inspecting and Adjusting Belt Alignment and
Tension
Procedure
1. Set the on/off switch in the “off” position, remove the A.C. line cord from the A.C. 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. Remove both stairarms as described in Procedure 7.17.
4. Operate the unit by rapidly rotating a crankarm by hand. As the unit operates watch the
drive belts for proper alignment. The belts should operate parallel to each other and the
belts should maintain even spacing.
5. If the belts are not correctly aligned...
THEN... OTHERWISE...
Continue with the next step. Skip to step 13
6. Refer to Diagram 5.3 for the following belt alignment steps.The right and left step up belt
tension bolts have locking tabs. If necessary, use pliers to bend the locking tabs out of the
way so that the bolts can be turned.
7. If the step up pulley belt is out of alignment to the right, continue with step 9.
8. If the step up pulley belt is out of alignment to the left, continue with step 11.
9. Turn the left step up belt tension bolt 1/4 turn clockwise, then repeat step 4. If turning the left
adjustment bolt 1/4 of a turn was not sufficient, turn the right step up belt tension bolt 1/4 of
a turn counterclockwise.
10. Repeat step 8, alternating between the left and right step up belt tension bolts until the
alignment is correct. Continue with step 13.
11. Turn the right step up belt tension bolt 1/4 of a turn clockwise, then repeat step 4. If turning
the right step up belt tension bolt 1/4 of a turn was not sufficient, turn the left step up belt
tension bolt 1/4 turn counterclockwise.
12. Repeat step 11, alternating between the right and left step up belt tension bolts until the
alignment is correct.

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13. Belt tension must now be checked and if necessary corrected. Remember, if it is necessary
to change belt tension, the belt alignment must be maintained.
Diagram 5.3 - Drive Unit
14. Place a belt gauge (Precor part # 20030-117 or equivalent) in the middle of the step up belt
at the center of the belt span (see Diagram 5.4). Lay a straight edge along the length of the
belt and beside the belt gauge. Slide one of the o-rings up against the shoulder of the belt
gauge. Press downward on the belt gauge, causing the belt to deflect. Read the deflection
on the belt gauge at the edge of the straight edge. Deflect the belt 1/4”. Read the tension
across the top edge of the o-ring. If the belt is correctly tensioned the gauge will read
between 14 and 16 pounds.
15. If the tension in step 14 is correct skip to step 18. Otherwise continue with the next step.
Input
Belt
Step Up
Belt
Tensioner
Input Belt
Step Up Belt
Tension Bolt
Input Belt
Tension Bolt
Adjustment
Slot

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Diagram 5.4 - Measuring Belt Tension
16. If the locking tabs on the right and left step up belt tension bolts have not been straightened,
use pliers to bend the locking tabs out of the way so that the bolts can be turned.
IF... THEN...
The belt tensioning gauge reads Turn both tension bolts
less than 14 pounds clockwise, in equal quarter-turn
increments, until the belt tensioning
gauge reads 14 - 16 pounds @1/4” deflection.
The belt tensioning gauge reads Turn both tension bolts
more than 16 pounds counterclockwise, in equal
quarter-turn increments, until the belt
tensioning gauge reads 14 - 16 pounds @ 1/4”
deflection.
17. Verify that the belt alignment is still correct by performing the procedure in step 4.
18. When both the step pulley belt tension and alignment are correct, use pliers to bend the
tension bolt locking tabs into the “locking” position.
19. The input pulley tension must now be checked and corrected, if necessary. There is not
sufficient room to use the belt tension gauge to set the input pulley belt tension. It will be
necessary to use the correctly tensioned step up belt as a comparison to set the input belt
tension.
20. Using your finger, press in on the center of the step up pulley belt to get a feeling of how
much pressure it takes to deflect the belt a 1/4”.
15 lbs
1/4”

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21. Using your finger, press in on the center of the lower span of the input belt. Compare the
pressure required to deflect the input belt to the pressure required to deflect the step up belt.
22. Loosen the input belt tensioner axle bolt slightly. Slide a stout screwdriver blade into the
adjustment slot (See Diagram 5.3) to the left of the pulley. Using the screwdriver as a lever,
press the pulley to the right. While maintaining constant pressure on pulley, check the belt
tension with your finger. When the belt tension feels correct, tighten and torque the input
belt tension bolt to 200 in./lbs.
23. Replace the stairarms per Procedure 7.17.
24. Check the operation of the unit as described in Section Four, then re-install the rear cover
as described in Procedure 7.1

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Procedure 5.3 - Calibrating the Lift Motor
1. In order to calibrate the lift motor, it is necessary to disconnect the lift motor from the ramp
assembly.
2. Set the on/off switch in the “off” position. Remove the front cover per Procedure 7.1.
3. Remove the four screws that retain the lift yoke to the ramp assembly. Support the lift motor
and ramp assembly as you separate the lift yoke from the ramp assembly. Lower the ramp
assembly until it is resting on the frame. (See Diagram 5.5)
Diagram 5.5 - Lift Motor Calibration
4. Set the on/off switch in the “on” position. Enter the diagnostics routine per Procedure 2.1.
After the L.E.D. test is complete, power bits will be displayed. Press the ENTER key to
display the lift calibration number.
5. Operate the CROSSRAMP  or CROSSRAMP keys as required to set the lift calibration
number to 127.
6. Rotate the lift yoke on the lift motor drive screw until the distance from the upper surface of
the plastic nut in the lift yoke to the end of the drive screw is 9”. If the lift motor drive screw
rotates the lift calibration number will no longer be 127. The lift calibration number must be
127 and the distance measurement must be correct for the lift calibration to be correct. See
Diagram 5.5.
Lift Yoke
9”
Retaining Bolt and Nut

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7. Set the on/off switch in the “off” position. Do not exit the diagnostic program in the normal
manner. Exiting the diagnostic program will cause the lift to self center and invalidate the lift
calibration just performed.
8. Raise the ramp assembly to a convenient height and slide the lift yoke into the ramp
assembly. Hand tighten the four lift yoke mounting screws and then torque them to
240 in/lbs.
9. Set the on/off switch in the “on” position. Thoroughly test all lift related functions per Section
Four.
10. Set the on/off switch in the “off” position, replace the front cover per Procedure 7.1.