Precor C844 User manual

C844 Upright Cycle
Page 1
C844 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.
© 2003 Precor Incorporated
Unauthorized Reproduction and Distribution Prohibited By Law

C844 Upright Cycle
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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 C844,
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 C844, the power cord must be disconnected from the wall outlet.
Always ensure that the C844 is unplugged from the wall outlet when you inspect or adjust the
C844, or when you isolate, remove, or replace a C844 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 C844 operation.
• The flywheel is very heavy. Be prepared for the weight of the flywheel when it comes off of
the flywheel shaft.
Caution statements are intended to prevent damage to the C844 as a result of the current
activity. Caution statements included in this manual are listed below:
• Notice the orientation notch on the PROM (U3). These components must be positioned with
the same notch orientation.
• When it is necessary to lift the C844, ensure that the C844 has adequate support. Do not lift
the C844 by the front cross-member.
Safety guidelines you should know and follow include:
• Read the owner’s manual and follow all operating instructions.
• Visually check the C844 before beginning service or maintenance operations. If it is not
completely assembled or is damaged in any way, exercise extreme caution while operating

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and checking the C844.
• When operating the C844, 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 C844.
• To prevent electrical shock, keep all electrical components, such as the power cord and
circuit breaker away from water and other liquids.
• Do not use accessory attachments that are not recommended by the manufacturer, such
attachments might cause injuries.
General Information
For the latest exploded view, part number and part pricing information, visit the Precor dealer
website at “www.precor.com/Dealer.

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Required Tools and Equipment
The following is a summary of the tools and equipment that may be required when you service a
Precor C844 Upright 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
Equipment
Anti-static kit
Digital multimeter
Supplies
Cable ties

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Procedure 2.1 - Performing C844 Cycle Diagnostics
This procedure tests or displays the following:
• Display Array
• Seven Segment Displays
• Baseline Resistance
• Software Revision Number
• Heart Rate Diagnostic
• Power Bits
• Keypad Test
1. Plug the power cord into the wall outlet, then turn on the cycle with the ON/OFF switch.
2. With the PRECOR C844 banner scrolling, press the STOP, WORK LEVEL UP and WORK
LEVEL DOWN keys simultaneously.
3. Verify that the entire left display window illuminates, then two diagonal lines sweep across
the display.
4. Watch the electronic display as the LED test progresses. This test is programmed to display
the following LED illumination sequence:
a. Every LED on the left display window illuminates simultaneously;
b. Horizontal, vertical, and diagonal lines of illuminated LED’s sweep across the left display
window;
c. The right display windows illuminate, then decrement from 8.8.8.8 to 0.0.0.0;
d. The function LED’s illuminate simultaneously and then extinguish; and
e. Each function LED illuminates separately and then extinguishes.
5. If you do not observe the LED illumination sequence described in the previous steps . . .
THEN . . . OTHERWISE . . .
Replace the upper PCA as described Continue with the next step.
in Procedure 7.1.

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6. Make a note of the Baseline Resistance numbers displayed on the electronic console.
Individually press the WORK LEVEL keys and verify that the Baseline Resistance numbers
change as the WORK LEVEL keys are pressed.
7. The software version number is displayed on the electronic console. Press ENTER, then
release.
8. HArt is displayed in the right display window. Put on the heart rate monitor.
9. While using the Heart Rate Transmitter, verify that the HEART RATE indicator blinks in time
with your heart beat and the heart rate information displayed is correct . . .
THEN . . . OTHERWISE . . .
Diagnostic software HArt mode checks Refer to the Smart Rate System
correctly; continue with the next step. Service and Maintenance Manual.
10. Press ENTER, then release. The power bits is displayed on the electronic console. Press
ENTER, then release.

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Note: Seven dots are displayed in the center of the left window.
As you press each key listed in Step 11, the column of the left display window corresponding to
the key pressed should illuminate. When you release each key, the column of light should be
replaced by a single dot.
11. Press each key listed:
BLANK
ENTER
BLANK
STOP
WORK LEVEL UP
WORK LEVEL DOWN
12. If the appropriate sections of the left display window illuminated when the corresponding
keys were pressed . . .
THEN . . . OTHERWISE . . .
The keypad test passed successfully; Replace the upper PCA as described
continue with the next step. in Procedure 7.1.
13. Press ENTER and WORK LEVEL UP to return to the PRECOR C844 banner.

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Procedure 2.2 - Displaying the Odometer
This procedure displays total distance (in miles or kilometers).
1. Plug the power cord into the wall outlet, then turn on the bike with the circuit breaker.
2. With the PRECOR C844 banner scrolling, press the STOP and WORK LEVEL UP keys
simultaneously and hold them until the message CYCLE ODOMETER scrolls across the left
display window.
Note: The right display window displays total miles or kilometers on the cycle (see
Diagram 2-2). The top display window shows the most significant bits of the number; the
lower display window shows the least significant bits of the number. The number
displayed is 102,187,723 (in miles or kilometers).
3. Press ENTER twice to return to the User ID prompt.
Diagram 2-2. Odometer Reading For the C844 Cycle
0001
0218
7723

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Procedure 2.3 - Selecting Club Settings
This procedure allows the modification of the following settings:
• U. S. Standard/Metric
• Line Voltage Selection
• Get Max Workout Time
1. Plug the power cord into the wall outlet, then turn on the cycle with the ON/OFF switch.
2. With the PRECOR C844 banner scrolling, press the QUICKSTART and WORK LEVEL ▲
keys simultaneously. Across the left display window scrolls either the banner U. S.
Standard or the banner Metric.
3. If you wish to change the measurement standard . . .
THEN . . . OTHERWISE . . .
Use the UP or DOWN keys to toggle Continue with the next step.
to an alternate measurement standard;
then continue with the next step.
4. Press ENTER, then release. The line voltage currently selected is displayed on the left
display window.
5. If you wish to toggle to the alternate line voltage. . .
THEN . . . OTHERWISE . . .
Use the UP or DOWN keys to toggle Continue with the next step.
to the alternate line voltage; then
continue with the next step.
6. Press ENTER, then release. The maximum workout time is displayed on the left display
window.
7. If you wish to change the maximum workout time . . .

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THEN . . . OTHERWISE . . .
Use the UP or DOWN keys to select Continue with the next step.
the new maximum workout time;
then continue with the next step.
8. Press ENTER, then release to return to the C844 Cycle banner.