Precor C762 User manual

C762, C764, C764i Stairclimber
Page 1
C762, C764, C764i Stairclimber
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
20039-105

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Section One - Things You Should Know
About This Manual
This manual is written for you, the C760 Series Climber service technician. The objective of this
service manual is to provide you with the instructions you need to maintain, inspect and adjust
C760 Series Climbers, troubleshoot malfunctions, and remove and replace components. This
manual includes the sections and appendices described in the following paragraphs.
Section One, Things You Should Know. This section includes warning and caution statements,
safety guidelines, and a list of required tools and equipment. It is highly recommended that you
read this section, as well as the C764/C762 Climber Owner’s Manual, before performing the
maintenance procedures provided in this manual.
Section Two, Software Features. The C760 Series Climbers are programmed with several
diagnostic and setup features. This section contains the procedures you need to access these
features.
Section Three, Preventive Maintenance. This section provides regular (scheduled)
maintenance activities that should be performed to keep the C760 Series Climbers in peak
condition.
Section Four, Checking Unit Operation. This procedure provides you with a quick way of
checking the climber operation. Check the climber operation at the end of a maintenance
procedure and when it is necessary to ensure that the climber is operating properly.
Section Five, 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 climber
components. This section provides you with the step-by-step procedures required to make these
adjustments.
Section Six, 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 Seven, Replacement Procedures. When a C760 Series Climber component must be
replaced, go to this section and follow the step by step instructions required to remove and
replace the malfunctioning component.
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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Miscellaneous Information
Right, Left, Front, and Back Conventions
In this manual, right, left, front, and back are from the perspective of a user standing on the
climber, facing the display enclosure.
Anti-Static Handling Procedures
The C760 Series Climbers contain some static-sensitive devices. Wrist straps dissipate static
before it can damage static-sensitive devices you are servicing. Use anti-static handling
procedures and wear an anti-static device (such as a wrist strap) when you perform this
procedure. Anti-static kits can be ordered from Precor Customer Service (Precor part number
20024-101).
Wrist straps are made for static control.They will neither reduce or increase the risk of electrical
shock when using or working on electrical equipment. When you wear a wrist strap, follow the
same precautions you would use if you were not wearing a wrist strap.
Diagram 1.1 - C762, C764 Stairclimber

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Version A and Version B Disk Assemblies
Diagram 1-2 shows the Version A and Version B disk assembly shafts. The Version B disk
assembly shaft has shoulders, the Version A disk assembly shaft does not. The Version A and
Version B disk assemblies are interchangeable. The part number for the Version A disk
assembly is 36020-101. 36020-102 is the part number for the Version B disk assembly.
Diagram 1.2 - Version A & B Disk Assembly Shafts
Version A
Version B
Shoulder

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Warning, Caution Statements and Safety Guidelines
WARNING and Caution statements are used throughout this manual to protect both you and the
C760 Series Climber. Additional precautions and guidelines are provided to ensure your safety
when servicing an C760 Series Climber.
WARNING statements indicate a particularly dangerous activity. WARNING statements you will
find in this manual include:
• To remove power from the C760 Series Climber, the power cord must be disconnected from
the wall outlet.
• Removing the covers exposes potentially dangerous machinery and high voltage
components. Use caution when performing maintenance operations with the covers off.
• While performing this procedure, you will be very close to high voltage components. Protect
yourself by removing jewelry (especially from ears, neck, and hands), tying up long hair, and
removing neck ties.
• If the climber is left in Calibration Mode for over 30 minutes, the magnet will become very
hot and the lower PCA may fail. Allow the magnet to cool by removing power from the
climber and waiting four hours with the covers off before you perform maintenance
operations or operate the climber.
• If the user’s heart rate has reached or exceeded the maximum heart rate. The user MUST
consult a physician before operating the C760 Series Climber.
Caution statements are intended to prevent damage to the C760 Series Climber as a result of
the current activity. Caution statements included in this manual are listed below:
• Remove power from the climber before you measure the resistance of the magnet.
• Notice the orientation notch on the PROM (U3). The new PROM must be positioned with the
same notch orientation. Replacing the PROM backwards will damage or destroy the PROM.
• Insert the new PROM carefully. Take care not to bend the legs of the PROM.
Safety guidelines you should know and follow include:
• Read the Owner’s Manual and follow all operating instructions.
• Operate C760 Series Climbers on a solid, level, dry surface.
• Visually check the C760 Series Climber before beginning service or maintenance
operations. If the climber is not completely assembled or if it is damaged, exercise extreme
caution while operating and checking the C760 Series Climber.

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• Be aware that the weight limit for the C760 Series Climber is 350 pounds.
• Keep all electrical components, such as the power cord and the ON/OFF switch, away from
water and other liquids.

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Required Tools and Equipment
The following list is a summary of the tools and equipment required by the procedures in this
manual. We recommend that you have this equipment available when you service C760 Series
Climbers.
TOOLS EQUIPMENT
#2 phillips screwdriver anti-static wrist strap
#2 flat-head screwdriver ohmmeter
voltmeter
1/8”, 5/32”, and 3/16” allen wrenches blue loctite
3/8”, 7/16”, 1/2” (2), 3/4”, and 17mm (2) cable ties
open end wrenches damp cloth
mild detergent
1/2” drive socket wrench set tape
chip puller
feeler gauge (0.030")
feeler gauge (0.050")
needle nose pliers
pliers
snap ring pliers

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Eddy Current Resistance and the C760 Series Climber
Magnetism
When the disk rotates, it “cuts” the lines of force that make up the magnetic field. As the lines of
force are cut, voltage is induced in the disk. The current produced by this induced voltage is
called eddy current.
How Eddy Current Works
Current flowing through a conductor produces a magnetic field. When the disk rotates, the
magnetic field produced by the eddy current in the disk opposes the magnetic field produced by
the magnet. Opposing magnetic fields repel each other like poles of a magnet repel each other.
This repelling action produces the resistance the user works against when operating the C760
Series Climber.
Increasing the Resistance
When the user presses the WORK LEVEL ▼ key, the current flowing through the magnets
increases. The increase in current increases the strength of the magnetic field. The disk cuts
more lines of force in the magnetic field and a greater voltage is induced on the disk. Because
current is proportional to voltage, the eddy current increases as well.
When the eddy current increases, the magnetic field produced by the eddy current increases and
opposes the magnetic field produced by the magnet with more strength. Because the two fields
are repelling more strongly, the resistance of the climber increases, thus allowing the user’s
speed to decrease.
Decreasing the Resistance
When the user presses the WORK LEVEL ▲ key, the current flowing through the magnet
decreases, causing the strength of the magnetic field to decrease as well.
As the disk rotates and cuts fewer lines of force in the magnetic field, a smaller voltage is induced
on the disk. As the voltage decreases, the eddy current also decreases.
When the eddy current decreases, the magnetic field produced by the eddy current decreases
and opposes the magnetic field produced by the magnet with less strength. Because the two
fields are repelling less strongly, the resistance of the climber decreases and the user’s speed
increases.

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Procedure 2.1 - Determining Software Version and Total
Floors Climbed
Software version numbers are invaluable for tracking and identifying problems and staying aware
of changes to the operation and features of the product. Units manufactured after May 28, 2000
(software version 6.20) Utilize standard access codes. See Diagrams 2.1 and 2.2 for key number
assignments.
Procedure
1. Plug the power cord into the wall outlet, then turn on the climber with the ON/OFF switch.
2. On units manufactured prior to May 29, 2000, at the PRESS ENTER FOR PROGRAMS
prompt, press the WORK LEVEL ▲and WORK LEVEL ▼keys simultaneously. The C762
display is shown in Diagram 2.1 and the C764 display is shown in Diagram 2.2
3. On units manufactured after May 28, 2000, press keys RESET, 6,5, sequentially. The C762
display is shown in Diagram 2.1 and the C764 display is shown in Diagram 2.2
4. The version number of the PROM is displayed in the upper right alpha-numeric display.
5. Press and release the ENTER key. The total number of floors is displayed in the upper right
alpha-numeric display.
6. Press the RESET or ENTER key to return to the PRESS ENTER FOR PROGRAMS
prompt.
Note:
If you cannot determine the software version number in this manner, look at the PROM (U8)
mounted on the upper PCA. A label on U8 indicates the software version number.

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Diagram 2.1 - C762 Stairclimber Display
Diagram 2.2 - C764 Stairclimber Display
Key #3
Key #2
Key #1
Key #5 Key #6 Key #7
Key #1 Key #2 Key #3
Key #5 Key #6 Key #7

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Procedure 2.2 - Performing Keypad and Display Diagnostics
Procedure
1. Plug the power cord into the wall outlet, then turn on the climber with the ON/OFF switch.
2. Units manufactured after May 28, 2000 (software version 6.20) Utilize standard access
codes. See Diagrams 2.1 and 2.2 for key number assignments.
3. On units manufactured prior to May 29, 2000, at the PRESS ENTER FOR PROGRAMS
prompt, press and hold the ENTER key, then press the WORK LEVEL ▲key until the
DISPLAY TEST message is displayed. The C762 display is shown in Diagram 2.1 and the
C764 display is shown in Diagram 2.2.
4. On units manufactured after may 28, 2000, press keys RESET, 5,1,7,6,5,7,6,1, sequentially.
The C762 display is shown in Diagram 2.1 and the C764 display is shown in Diagram 2.2.
5. Watch the electronic console as the display test progresses. This test is programmed to
display the following LED illumination sequences:
a. A vertical line and then a horizontal line scrolls across the left LED matrix.
b. The display segments on each right side alpha-numeric illuminate simultaneously for
each digit.
c. The LEDs to the left of the first column of functions illuminate, followed by the LEDs to
the second and third column.
4. If the appropriate sections of the electronic console illuminate as described in the previous
step...
THEN... OTHERWISE...
The display test is successful; continue Replace the upper PCA as described
with the next step. in Procedure 7.2.
5. The display will indicate whether heart rate is or is not installed. Press ENTER to continue.
6. When the NO KEYS message is displayed on the electronic console, press each of the keys
listed in the left column of Table 2.1. Verify that the message across from each function key
name is displayed on the electronic console as the key is pressed.
7. If the appropriate messages are displayed on the electronic console when you press the
keys listed in Table 2.1...

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THEN... OTHERWISE...
The keypad test is successful; continue Go to Step 3 of Procedure 6.2.
with the next step.
8. Press RESET. The message KEY PRESSED PLEASE WAIT is momentarily displayed on
the electronic console. When the PRESS ENTER FOR PROGRAMS prompt is displayed,
continue with the next step.+
Note:
The keys on the left keypad are the RESET keys and two hidden keys. The two hidden keys are
called 'hidden key next to reset' and 'left most hidden key'.
Table 2.1 - Electronic Console Keypad Test
KEY TO BE PRESSED MESSAGE TO BE VERIFIED
Left CHANGE Key CHANGE 1
Middle CHANGE Key CHANGE 2
Right CHANGE Key CHANGE 3
ENTER ENTER
WORK LEVEL ▼LEVEL DOWN
WORK LEVEL ▲LEVEL UP
QUICK START QUICK START
Key to the left of RESET (hidden) HIDDEN KEY NEXT TO RESET
Key on the far left of the console (hidden) LEFT MOST HIDDEN KEY
Key on the far right of the console (hidden) RIGHT MOST HIDDEN KEY
9. Press two or more keys on the left keypad. Verify that the MULTIPLE KEYS ON LEFT
KEYPAD message is displayed on the electronic console.
10. Press two or more keys on the right keypad. Verify that the MULTIPLE KEYS ON RT
KEYPAD message is displayed on the electronic console.
11. Press one or more keys on both the right and left keypads. Verify that the MULTIPLE KEYS
ON L AND R KEYPDS message is displayed on the electronic console.
12. Press the RESET key to return to the PRESS ENTER FOR PROGRAMS prompt.
13. Turn off the climber with the ON/OFF switch, then unplug the power cord from the wall
outlet.

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Procedure 2.3 - Selecting Club Settings
Procedure
1. Plug the power cord into the wall outlet, then turn on the climber with the ON/OFF switch.
2. Units manufactured after May 28, 2000 (software version 6.20) Utilize standard access
codes. See Diagrams 2.1 and 2.2 for key number assignments.
3. On units manufactured prior to May 29, 2000, at the PRESS ENTER FOR PROGRAMS
prompt, press and hold all three CHANGE keys simultaneously until the CHOOSEUNITS
[M/DN FT/UP] prompt is displayed.
4. On units manufactured after may 28, 2000, press keys RESET, 5,6,5,1,5,6,5, sequentially.
The C762 display is shown in Diagram 2.1 and the C764 display is shown in Diagram 2.2.
5. Press the WORK LEVEL ▲key to select U. S. Standard units. Press the WORK LEVEL ▼
key to select the Metric measurement system.
6. When the MAX WORKOUT prompt is displayed, use the ▲or ▼keys to designate a
workout time limit between 10 and 240 minutes. Press ENTER when the desired time
appears. The MODIFY CUSTOM prompt displays.
7. If you plan to modify the custom course currently selected...
THEN... OTHERWISE...
Press the WORK LEVEL ▼ key; then Press the WORK LEVEL ▲ key; then
continue with the next step. skip to Step 7.
Note:
When the CHOOSE COURSE USE UP/DOWN OR PRESS ENTER prompt appears, either the
digit '1' or the digit '2' is displayed in the left LED matrix.
8. To change the custom course, press either the WORK LEVEL ▲or WORK LEVEL ▼key.
The digit in the left LED matrix will cycle from '1' to '2' or '2' to '1'.
Note:
Instructions for designing custom courses are provided in the C760 Series Climber Owner's
Manual.
9. Press the RESET key to return to the PRESS ENTER FOR PROGRAMS prompt.

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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 isolate 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
Customer Service.
When a problem occurs, record the following information:
• Model and serial number
• Software version number
Note:
Determine the version number of the PROM mounted on the upper PCA as described in
Procedure 2.1 or by looking at the label on the PROM.
• 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 (performed on a regular basis by the
owner) or unscheduled (performed when you make a service call). Maintenance performed by
the owner is limited to cleaning and visually inspecting the climber and making the adjustments
specified in the C760 Series Owner's Manual. 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 C760 Series Climbers and their operating environment will keep maintenance
problems and service calls to a minimum. For this reason, Precor recommends that the following
preventive maintenance schedule be followed.
At the End of Each Day
• Wipe down the stair arms and frame with a damp cloth.
Every Week
• Wipe the surface of the electronic console with a barely-damp sponge or soft cloth. Dry with
a clean towel.
• Vacuum underneath the climber, following these steps:
a. Turn off the climber with the circuit breaker, then unplug the power cord from the wall
outlet.
b. Place the climber on one side (either side will do).
c. Vacuum the rug or “damp mop” the floor.
d. Make sure that the floor is dry before returning the climber to an upright position.
On-Site Preventive Maintenance (Service Technician)
Perform the following preventive maintenance tasks each time you are called to service a C760
Series Climber:
• Examine the belts, sheave, disk, and bearings for wear, cracks, or other signs of
deterioration and replace if necessary.
• Visually inspect the power cable harness. Replace the power cable harness if it is torn or
damaged.

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• Check the LEDs mounted on the upper PCA and the function keys displayed on the
electronic console by performing Procedure 2.2.
• Measure the gaps between the disk and the magnet assemblies as described in Procedure
5.1.
• Visually examine all wires and check connectors and wire connections. Secure connections
and replace wiring as necessary.
• When the covers are removed, visually inspect the lower ribbon cable and the part of the
upper ribbon cable that is not inside the column. If either ribbon cable is torn or damaged,
replace it as described in Procedure 7.10.
• Inspect the stair arm and drive belts. If the belts show signs of wear or damage, remove and
replace the belts as described in either Procedure 7.15 and Procedure 7.20.

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Section Four - Checking Unit Operation
This section provides you with a method of checking climber operation. Check climber operation
at the end of a maintenance procedure and when it is necessary to ensure that the climber is
operating properly.
Procedure
1. Plug the power cord into the wall outlet, then turn on the climber by using the circuit breaker.
2. When the PRESS ENTER FOR PROGRAMS prompt appears, press QUICK START.
3. Select Work Level 1 and press ENTER.
4. Operate the climber 4–5 minutes. As you operate the climber:
a. Concentrate on the resistance of the climber and the sound of the stair arm belts and
return springs as you pedal. Be on the alert for unusual rubbing, hitting, grinding, or
squeaking noises
b. Press the Change keys. Verify that information such as Horizontal Distance and Steps
Per Minute changes as the workout progresses.
c. Make sure that the stair arm belts do not rub on the cover and that the cover bracket
does not rub on the sheave.
5. If you feel no resistance as you step, if the climber makes unusual noises, or the electronic
display does not change appropriately...
THEN... OTHERWISE...
Refer to Section 6 Continue with the next step.
6. Press the WORK LEVEL ▲key until you reach Work Level 5. Operate the climber for
another 2–3 minutes.
7. If the climber resistance does not change or the climber operation feels inconsistent
compared with Work Level 1...
THEN... OTHERWISE...
Refer to Section 6 Continue with the next step.
8. Press the WORK LEVEL ▲key until you reach Work Level 10. Operate the climber for
another 2–3 minutes.

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9. If the climber resistance does not change or the climber operation feels inconsistent
compared with Work Levels 1 and 5...
THEN... OTHERWISE...
Refer to Section 6. Continue with the next step.
10. Check the LEDs mounted on the upper PCA and the function keys displayed on the
electronic console by performing Procedure 2.2.
11. Turn off the climber with the circuit breaker, then unplug the power cord from the wall outlet.

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Procedure 5.1 - Inspecting and Adjusting the Gaps Between
the Disk and the Magnet Assemblies
Procedure
1. Remove the covers as described in Procedure 7.1.
WARNING
Before performing maintenance operations with the covers removed, review the Warning and
Caution statements listed in Section One, Things You Should Know.
2. Press down the stairarm with one hand. With your other hand, grasp and pull the end of the
stairarm belt connected to the return spring. Release the stairarm. Remove the belt from the
pulley and belt idler (see Diagram 5.1).
Diagram 5.1 Removing a Stairarm Belt
3. Place the .050 feeler gauge between the disk and the top coil on the right magnet assembly
Stairarm Belt
Stairarm
Return
Spring
Toothed
Pulley

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4. If the .050 feeler gauge does not fit snugly...
THEN... OTHERWISE...
Continue with the next step. Skip to Step 7.
5. Barely loosen the bolts, lock washers, and flat washers that secure the right magnet
assembly to the climber frame (see Diagram 5.2).
Diagram 5.2 - Magnet Assemblies
Note:
Do not loosen the bolts too much. Although you must be able to move the magnet assembly
Disk Assembly
Magnet Assemblies
Cable
Clamp