Precor C842i User manual

C842i, C846i Upright and Recumbent Cycle
Page 1
C842i, C846i Bicycle
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 sitting on the C842i or
C846i, 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 C842i, or C846i, the optional power adapter must be
disconnected from the cycle. Always ensure that the optional power adapter is disconnected
from the cycle when you inspect or adjust the C842, C842i, C846 or C846i, or when you
isolate, remove, or replace a component.

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• Removing the covers exposes high voltage components and potentially dangerous moving
parts. 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 operation.
• Caution statements are intended to prevent damage to the bicycle as a result of the current
activity. Caution statements included in this manual are listed below:
Safety guidelines you should know and follow include:
• Read the owner’s manual and follow all operating instructions.
• Visually check the bicycle 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 bicycle.
• When operating the bicycle, 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. While servicing, never
place liquids on any part of the bicycle The water bottle holder must be empty.
• To prevent electrical shock, keep all electrical components, such as the power cord and
power adapters away from water and other liquids.
• Do not use accessory attachments that are not recommended by the manufacturer, such
attachments might cause injuries or damage to the unit.
General Information
For the latest exploded view diagram, 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 is a summary of the tools and equipment that may be required when you service a
Precor C842i, or C846i Upright or Recumbent Cycle.
Tools
Phillip and flat-head screwdrivers
Standard and metric allen wrench set
Open-end wrench set
Socket wrench set
Chip puller
Rubber mallet
Snap ring pliers
Torque wrench
Pry bar
20030-119 secondary sheave tool
32 mm deep well socket
Equipment
Anti-static kit
Digital multimeter
Supplies
Cable ties

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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 cycle 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
• Turn off and, unplug the power adapter (if equipped) from the bicycle.
• Wipe down the covers, handlebars, seat and pedals with a damp cloth.
Daily Maintenance
Clean the bicycle’s frame, covers, seat and pedals using a water damped cloth. Wipe the surface
of the electronic console with a damp sponge or soft cloth. Dry with a clean towel.
Weekly Maintenance
• Clean underneath the bicycle, following these steps:
1. Turn off the bicycle with the on/off switch, then unplug it from the power adapter (if
equipped).
2. Place the bicycle on its side.
Note:
Place a drop cloth under the bicycle to protect the flooring and to ensure that the cycle 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 bicycle to an upright position.

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Quarterly Maintenance
1. Remove the cover.
2. Thoroughly clean inside the bicycle. Use a vacuum cleaner and damp rag all dust belt
particles, etc.
3. Check the belt tension of both belts per Procedures 5.1 and 5.2.
4. Replace both covers.
On-Site Preventive Maintenance (Service Technician)
When you are called to service a C842i, or C846i, perform these preventive maintenance
activities:
• Perform the software diagnostics. Check LED and keypad function. Record the odometer
reading. See Procedure 3.1.
• Check speed sensor function (is RPM or speed displayed when the unit is in operation?). If
not, see Procedure 6.4
• If the unit is operated at resistance level 1, does it turn freely and smoothly? If not, see
Procedure 6.6.
• Visually inspect the drive belts for cracks, fraying or excessive wear.
• Visually examine all wires and check connectors and wire connections. Secure connections
and replace wiring as necessary.

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Procedure 3.1 - Accessing the Diagnostic Software
The treadmill's diagnostic software consists of the following modes:
• Display Test
• Keyboard Test
• Heart Rate Test
• Machine Test
Procedure
1. Using the RESET key and the numeric keypad, press keys RESET,5,1,7,6,5,7,6,1, sequen-
tially.
2. Hardware Validation will scroll across the display followed by DISPLAY TEST.
Diagram 3.1 - C846i Display
Numeric
Keypad
OK Key
Back Key
Reset Key

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3. Press the OK key, the upper most group of LED’s will illuminate on the display. Check the
display to ensure that all LED segments are illuminated.
4. Press the OK key four more times to display the remaining LED groups. Check each display
group to ensure that all LED segments are illuminated.
5. Press the BACK key then the Tkey, KEYBOARD TEST will scroll across the display.
6. Press the OK key, a representation of all of the keys on the console will be displayed.
Pressing a key on the console will cause the representation of that key to go off. Press all of
the keys on the console to ensure that all of the keys are functioning.
7. Press and hold the BACK key then the Tkey, HEART RATE will be displayed.
8. Grasp both of the heart rate grips on the handlebar, after a couple of seconds the heart rate
will be displayed in the heart rate and smart rate displays.
9. Use chest strap transmitter or a test transmitter to test the wireless heart rate function, after
a couple of seconds the heart rate will be displayed in the heart rate and smart rate displays.
10. Press the BACK key then the Tkey, MACHINE TEST will scroll across the display.
11. Press the OK key, BRAKE test will be displayed.
12. Press the Tkey, PWRB will be displayed with the current power bit setting.
13. Press the BACK key, BRAKE test will be displayed.
14. Press the Tkey, RPM will be displayed with the current pedaling speed.
15. Press the BACK key, BRAKE test will be displayed.
16. Press the Tkey, BATTERY test will be displayed.
17. Press the OK key, the battery voltage will be displayed as XX.X VDC.
18. Press the RESET key to exit the hardware validation test.

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Procedure 3.2 - Information Display
Software version numbers are invaluable for tracking and identifying problems and staying aware
of changes to the operation and features of the product.
Procedure
The information display will access the following data;
• Odometer
• Hour Meter
• U-Boot Software
• U-Base Software
• Lower Software
• Serial Number
• Usage log
• Error Log
Procedure
1. Plug the power cord into the wall outlet, then turn on the treadmill with the circuit breaker.
2. With the PRECOR banner scrolling, press the keys RESET,6,5, sequentially.
3. DIAGS-INFORMATION DISPLAY will scroll across the display.
4. Use the S,Tkeys to move to the desired display shown in the list above.
5. ODOMETER display. Press the OK key.
6. The odometer will be displayed as XXX miles.
Note: The odometer data is stored in non-volatile memory on the upper PCA. If the upper PCA
is replaced the odometer data will be lost.
7. Press the BACK key to exit the odometer display.
8. HOUR METER display. Press the OK key.
9. The operating time of the unit will be displayed as 12345 HOURS. The operating time is
defined as total amount of time that the unit has operated in program modes with the drive
motor running. The hour meter is also used to provide the “time stamp” for the error code
log.
10. Press the BACK key to exit the hour meter display.

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11. U-BOOT SW display. This display the installed version of upper boot software. The boot
software is used to upload new software into the upper display PCA.
12. Press the OK key. The software part number will be displayed as XXXXX-XXX.
13. Press the BACK key to exit the U-Boot SW display.
14. U-BASE SW display. This display the installed version of upper PCA software.
15. Press the OK key. The software part number will be displayed as XXXXX-XXX.
16. Press the BACK key to exit the U-Base SW display.
17. LOWER SW display. This display the installed version of lower PCA software.
18. Press the OK key. The software part number will be displayed as XXXXX-XXX.
19. Press the BACK key to exit the lower SW display.
20. SER. NUMBER display. Press the OK key.
21. The treadmill’s serial number will be displayed. The serial number may be incorrect or not
displayed if the upper PCA has been replaced.
22. Press the BACK key to exit the serial number display.
23. USAGE LOG display. Press the OK key.
24. Use the S,Tkeys to move through the list of programs. A message will scroll describing the
program, the number of times and the number of minutes the program was used.
25. Press the BACK key to exit the usage log display.
26. ERROR LOG display. Press the OK key, the quantity of errors in the log will be displayed.
27. Press the OK key, the most recent error will be displayed first.
28. Use the S,Tkeys to move through the list of errors. The error messages will list the error
name, the odometer reading when the error occurred, the hour meter when the error
occurred and the drive motor current reading when the error occurred.
29. Press the RESET key to exit the information display.

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Procedure 3.3 - Selecting Club Settings
Procedure
This procedure allows you to change the following club settings:
• Select Language
• Select Units
• Set Max Workout Time
• Set Max Pause Time
• Set Cool Down Time
• Set Resistance Range
• Set Custom Program
Procedure
1. Plug the power cord into the wall outlet, then turn on the treadmill with the circuit breaker.
2. With the banner scrolling, press keys RESET,5,6,5,1,5,6,5, sequentially.
3. Use the S,Tkeys to move to the desired display shown in the list above.
4. DIAGS-SET CLUB PARAMETERS will scroll across the display.
5. When SELECT LANGUAGE is displayed. Press the OK key.
6. Use the S,Tkeys to toggle between the available languages.
7. Press the BACK key to exit the select language display.
8. SELECT UNITS display. Press the OK key.
9. Use the S,Tkeys to toggle between U.S and METRIC measurements.
10. Press the BACK key to exit the set units display.
11. SET MAX WORKOUT TIME display. Press the OK key.
12. Use the S,Tkeys to select the maximum time a user can remain in a program.
13. Press the BACK key to exit the set max. workout time display.
14. SET MAX PAUSE TIME display. Press the OK key.
15. Use the S,Tkeys to select the maximum time a program will remain in the pause mode.
16. Press the BACK key to exit the set max. pause time display.

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17. SET COOL DOWN TIME display. Press the OK key.
18. Use the S,Tkeys to select the cool down time.
19. Press the BACK key to exit the set cool down time display.
20. SET RESISTANCE RANGE display. Press the OK key.
21. Use the S,Tkeys to select to HIGH, MEDIUM or LOW resistance range.
22. Press the BACK key to exit the set resistance range display.
23. SET CUSTOM PROGRAM display. Allows programing of the custom program. Follow the
instructions scrolling on the display to program the custom course. Use the ENTER key to
save changes and exit or the BACK to exit without saving changes.

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Procedure 3.4 - 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 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.).
d The frequency of occurrence.

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Section Four - Checking C842i, or C846i Operation
This section provides you with a quick method of checking operation.
Procedure
1. On C846 version 1 units, set the on/off switch in the “on” position.
2. Start pedaling.
3. With the banner displayed, press QUICK START.
4. Select Resistance Level 1 and press ENTER.
5. Operate the C842, C846 or C846i for 4–5 minutes. As you operate the bike, concentrate on
the operating sounds made by the unit. Be on the alert for unusual rubbing, hitting, grinding,
or squeaking noises.
6. If the bike makes unusual noises or the electronic display does not change appropriately,
troubleshoot per Section 6.
7. Press the RESISTANCE ▲ key until you reach Resistance Level 10. Operate the C846 for
another 2–3 minutes.
8. If the resistance does not change or the operation of the bike feels inconsistent compared
with Resistance Level 1, troubleshoot per section 6.
9. Press the RESISTANCE ▲ key until you reach Resistance Level 20. Operate the bike for
another 2–3 minutes.
10. If the resistance of the bike does not change or operation feels inconsistent with Resistance
Levels 1 and 10, troubleshoot per Procedure 6.5.
11. Check the LED’s mounted on the upper PCA and the function keys displayed on the
electronic console by performing Procedure 3.2.

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Procedure 5.1 - Primary Drive Belt Adjustment
1. Remove the left, right and top covers. Place the belt tension gauge, as shown in Diagram
5.1, on the primary belt.
Diagram 5.1 - Primary Belt Tensioning C842i, C846i
2. The belt gauge should read 95 pounds plus or minus 5 pounds. If the belt tension is
incorrect, loosen but do remove the idler pulley locknut. Insert a pry bar between the bottom
side of the idler pulley and the frame tab directly below the idler pulley. Carefully, pry the
idler pulley upward until the belt gauge reads 95 pounds. While maintaining the belt gauge
reading at 95 pounds, torque the idler pulley locknut to 120 inch pounds.
3. Check the secondary belt tension per procedure 5.2.
4. Replace the top and both side covers.
Belt
Gauge
Primary
Belt
Idler
Pulley
Idler Pulley Locknut

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Procedure 5.2 - Secondary Drive Belt Adjustment
1. Remove both side covers and the top cover. Place the belt tension gauge, as shown in Dia-
gram 5.2, on the secondary belt.
Diagram 5.2 - Secondary Belt Tensioning C842i, C846i
2. The belt gauge should read 90 pounds plus or minus 5 pounds.
3. The secondary belt tension is set by adjusting the position of the generator. Loosen but do
not remove the four generator mounting bolts. Loose the jam nut on the belt tension
adjustment bolt mounted on the generator (see Diagram X). Adjust the belt tension bolt until
the belt gauge reads 90 pounds.
4. Tighten the belt adjustment bolt’s jam nut. Torque the four generator mounting bolts to 150
inch pounds.
Secondary
Belt
Belt
Gauge
Generator

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Procedure 5.3 - Recumbent Seat Adjustment
1. Perform this procedure if the front to rear movement of the seat is too tight or there is
excessive side to side seat wobble.
2. Loosen but do not remove the four mounting screws on the left and right seat adjustment
plates. See Diagram 5.3
Diagram 5.3 - Recumbent Seat Adjustment (All versions)
3. Insert an allen bit into the adjustment hole in one of the seat adjustment plates. Rotate the
adjustment plate counterclockwise to loosen or clockwise to tighten the seat. Perform half of
the adjustment using the right hand adjustment plate and half of the adjustment using the
left hand adjustment plate.
4. Apply a minimum of pressure to the adjustment wrench when tightening the seat
adjustment. Apply only enough pressure to rotate the adjustment plate fully clockwise.
5. When the seat is properly adjusted, the angle of rotation of both adjustment plates should
be approximately the same. The seat should not wobble side to side and should move
forward and backward easily.
6. Torque the four seat adjustment plate mounting screws to 120 in/lb.
Adjustment
Plate
Mounting
Screw
Seat
Carriage
Adjustment
Wrench

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Procedure 6.1 - Troubleshooting the Interconnect Cables
Troubleshooting the upper interconnect cable
1. Remove the display housing per Procedure 7.13. Disconnect the upper interconnect cable
from the upper PCA.
2. Disconnect the upper interconnect cable from the junction block between the column and
the main frame.
.Diagram 6.1 - Interconnect Cables, C842i, C846i
3. Connect the by-pass interconnect cable to the upper PCA and the junction block.
4. Check the operation of the cycle as described in Section Four.
5. If the problem is still present re-connect the original upper interconnect cable and proceed
with step 25.
Troubleshooting the Lower Interconnect cable
6. Disconnect the lower interconnect cable from the lower PCA and the junction block.
7. Connect the by-pass cable to the junction block and the lower PCA.
8. Check the operation of the cycle as described in Section Four.
9. If the problem is still present, troubleshoot junction block
Heart Rate
Cables
Upper
Interconnect
Cable
Junction
Block
Lower
Interconnect
Cable

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Troubleshooting the Junction Block
10. Remove the display housing per Procedure 7.13. Disconnect the upper interconnect cable
from the upper PCA.
11. Disconnect the lower interconnect cable from the junction block. Connect the lower
interconnect cable to the upper PCA.
12. If you have performed all of the previous tests and have not been able to locate the trouble,
call Precor customer support.
13. Check the operation of the cycle as described in Section Four.

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Procedure 6.2 - Troubleshooting the Keypad
If the function keys on the electronic console are unresponsive, the problem may be either the
upper PCA or keypad. This troubleshooting procedure gives you the information you need to
determine which of these components is malfunctioning.
Procedure
WARNING
Before continuing with this procedure, review the Warning and Caution statements listed in
Section One.
1. If an error 5 is being displayed, continue with step 3. If one or more keys do not function,
skip to step 8.
2. Remove the screws that secure the upper display assembly to the upper handrail. Carefully,
pull some excess interconnect cable out from the targa upright. Rotate the display housing,
so that the rear of the upper PCA is facing upward, and set the display housing on the upper
handrail.
3. Attach the wrist strap to your arm, then connect the ground lead of the wrist strap to an earth
ground.
4. With the power off (not pedalling), disconnect the keyboard cable from the upper PCA.
5. Start pedalling, if the error 5 is no longer present, the key board is bad. If the error 5 is still
present, the upper PCA is bad. Replace either the keyboard (display housing) or the upper
PCA as appropriate.
6. Substitute a known good keyboard (display housing) to determine if the keyboard is
defective. If the keys not function normally, replace the original keyboard (display housing).
If the same key(s) still do not function, replace the upper PCA.
7. If you have performed all of the previous tests and have not been able to locate the trouble,
call Precor customer support.
8. The only means of determining if a non-functioning key is caused by the keypad or the
upper PCA is by substituting a known good part. The keypad is the more likely cause, try
substituting the display with keypad before the upper PCA.
9. If you have performed all of the previous tests and have not been able to locate the trouble,
call Precor customer support