Certificate No. 1,400,502, issued July 8, 1986. FlexDeck, Zone Trainer and Heart Rate Zone Training are trademarks of
Life Fitness. Any use of these trademarks, without the express written consent of Life Fitness, is forbidden.
U.S. Patent Numbers 3,767,195 and 4,358,105.
M051-00K40-A010
8-95
Life Fitness Model 4500HR Treadmill
INTRODUCTION
HOW TO USE THIS SERVICE MANUAL
In the unlikely event that an operating problem may occur with your Life Fitness model 4500HR aerobic trainer,
this Service Manual will instruct and guide you on the quickest, most efficient manner in which to approach the
situation. This Service Manual has been separated into a total of Four Sections for quick reference:
q INTRODUCTION
q TABLE OF CONTENTS
Section I
q TROUBLESHOOTING GUIDES
Section II
q DIAGNOSTIC TESTS
Section III
q MODEL 4500HR "How To..." GUIDES
Section IV
q WIRING DIAGRAMS
q PARTS IDENTIFICATION
q COMMUNICATING BY FAX
If an operating problem should arise, turn to the TROUBLESHOOTING GUIDES and attempt to isolate what is
causing the malfunction. The GUIDES are listed by symptoms and follow with suggestions as to the most probable
cause of the problem.
Once you have pinpointed the source of the problem, turn to the appropriate "How To..." section and review the
proper procedures for removing, replacing or adjusting a part. The "How To..." sections are organized by
replaceable part (or assembly) name and each page lists the “Tools Required“ to complete that specific function.
Refer to Section IV to identify the proper name and number of the part you will now need to order to repair your
machine. A form to order by FAX has also been included in Section IV for your convenience.
To order a part, call Life Fitness After Market Services any Monday through Friday from 8:00 AM to 6:00 PM
( C.S.T.). When you place a call, in order to speed our response to your particular situation, please have the
following information available for the customer service phone technician who will be prepared to assist you:
1. The Treadmill model type (4500HR)
2. The serial number ( Located on the front crossbar between the two wheels)
Serial Number:
3. The symptom of the problem you are experiencing
4. The part name and number you need to order
When you receive your order, review the appropriate "How To..." section and follow the step by step procedures
designed to help you install the part quickly and correctly.
If you have any questions or comments please phone, mail, or fax us at one of the numbers listed below.
INTRODUCTION (How to use this Service Manual)
TABLE OF CONTENTS
SECTION IPAGE
TROUBLESHOOTING GUIDES
THEORY OF OPERATION ..........................................................................................................................................1
NO POWER..................................................................................................................................................................2
STRIDING BELT ..........................................................................................................................................................4
UNIT RESETS RANDOMLY........................................................................................................................................5
DISPLAY DOES NOT ILLUMINATE OR RESPOND TO INPUT ................................................................................ 6
UNIT WILL NOT ELEVATE......................................................................................................................................... 7
MOTOR COVER ..........................................................................................................................................................2
HANDLEBAR AND HANDRAILS................................................................................................................................. 4
DECK AND STRIDING BELT ......................................................................................................................................5
FRONT ROLLER ASSEMBLY ....................................................................................................................................6
DRIVE MOTOR BELT..................................................................................................................................................12,13
DRIVE MOTOR ASSEMBLY.......................................................................................................................................14,15
PARTS IDENTIFICATION............................................................................................................ 2,3
COMMUNICATING BY FAX......................................................................................................... 4,5
Life Fitness Model 4500HR Treadmill
THEORY OF OPERATION
The operational functions of the Life Fitness Model 4500HR Treadmill are accomplished by four main components:
the Control Board , the Display Console, the Drive Motor and the Lift Actuator. The Treadmill user and the
control board provide input to the display console. The display console then determines the appropriate action to be
taken and passes low level signals to the control board. The control board converts low level signals to high level
signals and forwards them to the drive motor and the lift actuator to execute the requested command. All of the
“Intelligence” within the Treadmill is located in the display console.
Control Board
The control board provides power for the Treadmill, acts as an interface between the display
console, drive motor and lift actuator, and also acts as an additional interface between the speed
sensing and lift limit switches. The drive motor trigger, lift actuator time and direction, and safety
power relay signals are received from the display console and routed through the control board to
execute a command. Speed sensing and lift limit signals are also passed through the control board
to the display console.
Display Console
The display console is the user interface that allows selection from the various programs and options
offered by the Treadmill. The display console provides all of the “Intelligence” within the Treadmill,
controls the information displays, and monitors the keypad and safety switches. It determines the
drive motor and lift actuator actions to suit the chosen Life Fitness aerobic training program and it
also accommodates the optional heart rate receiver.
Drive Motor
The drive motor is the component responsible for moving the striding belt. The speed sensor, located
on the drive motor, sends pulses through the control board to the display console which converts
them to the striding belt speed. The display console adjusts the power to the drive motor to maintain
a constant speed to the striding belt resulting in a more comfortable “feel”.
Lift Actuator
The lift actuator is the component responsible for raising and lowering the incline level of the
Treadmill. The display console, through the control board, will raise and lower the lift actuator for the
appropriate amount of time and incline required by a specific command. The “Home” lift limit switch
signals the display console when the lift actuator is at 0% incline. The lift actuator also has its own
internal built-in limit switches.
1
Life Fitness Model 4500HR Treadmill
TROUBLESHOOTING GUIDE
Symptom: NO POWER
MalfunctionProbable CauseCorrective Action
No Power
On/off switch
Insufficient power sourcePlug treadmill into power source with proper
Secure connection at Receiver
Secure connection at Console and Handlebar.
Check Heart Rate kit operating instructions
Have different people try Transmitter (chest) strap.