Life Fitness Lifecycle 3500 Series User manual

Model 3500 Treadmill
SERVICE MANUAL
NET PRICE:
After Market Services

FCC Warning - Possible Radio/Television Interference
NOTE: This equipment has been tested and found to comply with the limits pursuant to Part 15 of the FCC rules. These limits are designed to provide
reasonable protection against harmful interference in a residential installation. Any changes or modifications not expressly approved by the party
responsible for compliance could void the user's authority to operate the equipment. This equipment generates, uses and can radiate radio frequency
energy and, if not installed and used in accordance with the instructions, may cause harmful interference to radio communications. However, there is
no guarantee that the interference will not occur in a particular installation. If this equipment does cause harmful interference to radio or television
reception, which can be determined by turning the equipment off and on, you are encouraged to try to correct the interference by one or more of the
following measures:
•Reorient or relocate the receiving antenna.
•Increase the space between the equipment and the receiver.
•Connect the equipment to an outlet on a different circuit than that to which the receiver is connected.
•Consult an exercise equipment dealer or an experienced radio/TV technician for help.
You are cautioned that any changes or modifications to this equipment could void your product warranty.

Life Fitness Model 3500 Treadmill
INTRODUCTION
HOW TO USE THIS SERVICE MANUAL
In the unlikely event that an operating problem may occur with your Life Fitness model 3500 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:
oINTRODUCTION
oTABLE OF CONTENTS
Section I
oTHEORY OF OPERATION
oTROUBLESHOOTING GUIDES
Section II
oDIAGNOSTIC TESTS
Section III
oMODEL 3500 "How To..." GUIDES
Section IV
oWIRING DIAGRAMS
oPARTS IDENTIFICATION
oCOMMUNICATING 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 (3500)
2. The serial number ( Located on the front crossbar between the two wheels)
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.
AFTER MARKET SERVICES
10601 Belmont Avenue, Franklin Park, IL 60131
Phone ( 800 ) 351-3737 Toll Free or ( 708 ) 451-0036
FAX [phone] Toll Free or [phone]
Serial Number:

Life Fitness Model 3500 Treadmill
TABLE OF CONTENTS
INTRODUCTION (How to use this Service Manual)
TABLE OF CONTENTS
SECTION I PAGE
THEORY OF OPERATION 1
TROUBLESHOOTING GUIDES
NO POWER................................................................................................................. 2
NOISY TREADMILL...................................................................................................... 3
STRIDING BELT........................................................................................................... 4
UNIT RESETS RANDOMLY........................................................................................... 5
DISPLAY DOES NOT ILLUMINATE OR RESPOND TO INPUT.......................................... 6
UNIT WILL NOT ELEVATE ............................................................................................ 7
ERROR DISPLAY MESSAGES..................................................................................... 8
HEART RATE DOES NOT RESPOND ........................................................................... 9
(If Equipped with Optional Heart Rate Kit Tray )
SECTION II
DIAGNOSTIC TESTS ................................................................................................................ 1-4
SECTION III
How To...REMOVE AND REPLACE THE
VENT COVER.............................................................................................................. 1
MOTOR COVER........................................................................................................... 2
DISPLAY CONSOLE .................................................................................................... 3
HANDLEBAR AND HANDRAILS .................................................................................... 4
DECK AND STRIDING BELT......................................................................................... 5
FRONT ROLLER ASSEMBLY ....................................................................................... 6
REAR ROLLER ASSEMBLY ......................................................................................... 7
HEATSINK CONTROL BOARD ASSEMBLY ................................................................... 8,9
DISPLAY WIRE HARNESS........................................................................................... 10
LIFT ACTUATOR ASSEMBLY ....................................................................................... 11
DRIVE MOTOR BELT................................................................................................... 12,13
DRIVE MOTOR ASSEMBLY ......................................................................................... 14,15
LIFESPRINGS.............................................................................................................. 16
TRAY ( Optional Heart Rate Kit ).................................................................................... 17
How To...ADJUST AND TENSION THE STRIDING BELT............................................................. 18,19
SECTION IV
WIRING DIAGRAM................................................................................................................... 1
PARTS IDENTIFICATION........................................................................................................... 2,3
COMMUNICATING BY FAX....................................................................................................... 4,5

1
Life Fitness Model 3500 Treadmill
THEORY OF OPERATION
The operational functions of the Life Fitness Model 3500 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.

2
Life Fitness Model 3500 Treadmill
TROUBLESHOOTING GUIDE
Symptom: NO POWER
Malfunction Probable Cause Corrective Action
No Power On/off switch Turn unit On.
Insufficient power source Plug treadmill into power source with proper
electrical requirements.
(See Operation Manual)
Line cord improperly seated in
electrical outlet Inspect power connection at outlet.
Damaged line cord Replace line cord.
Faulty Display Console See “Display Console “ symptom.

3
Life Fitness Model 3500 Treadmill
TROUBLESHOOTING GUIDE
Symptom: NOISY TREADMILL
Malfunction Probable Cause Corrective Action
Rubbing sound from
beneath machine Foreign objects may be stuck under the machine Inspect underneath Belt and Machine. Remove any debris or accumulation.
Rubbing sound from
Striding Belt Striding Belt not tracking properly
Striding Belt is rubbing on
extrusion or roller pulley
Striding Belt is rubbing on belt
guide
Adjust Striding Belt tracking. See “How
To...Adjust and Tension the Striding Belt”
Center Striding Belt. See “How To...Adjust and
Tension the Striding Belt”
Center Striding Belt. See “How To...Adjust and
Tension the Striding Belt”
Popping sound Insufficient break-in period
Wax accumulation on rear roller
A new Deck and Striding Belt will require a
break-in period of approx. 20 hours.
Run machine at 4 to 5 MPH to distribute wax
onto Striding Belt.
Squeaking noise Lifesprings may be out of
alignment Reposition the Lifesprings.
Drive Motor Belt may be worn or
damaged Replace Drive Motor Belt.
Drive Motor Pulley shifted Check Drive Motor Pulley to insure Pulley is
aligned with Front Roller Pulley. Tighten the
Set Screws to secure the Pulley into place.
“Groaning” sound heard
from front of machine Drive Motor Belt over-tensioned Slacken Drive Belt tension (See “How To...Remove and Replace the Drive Motor Belt”)
Weak Drive Motor/Drive Motor
Software Check Drive Motor Flywheel and Software for compatibility (See Diagnostic Software
Version.
Faulty Drive Motor Replace Drive Motor
Loud “Groaning” sound
heard from front of machine
while elevating
Faulty Lift Motor Perform “Lift Test”. (See Diagnostics).
Replace faulty Lift Motor.

4
Life Fitness Model 3500 Treadmill
TROUBLESHOOTING GUIDE
Symptom: STRIDING BELT
Malfunction Probable Cause Corrective Action
Striding Belt will not move Insufficient power source
Faulty Control Board
Plug treadmill into power source with proper
electrical
requirements. (See Operation Manual)
Replace Control Board
Striding Belt hesitates upon
start up (or will not begin to
turn on new machine)
High amount of friction between
Deck and Striding Belt. Start unit with no one on it at 3.5 mph and 5% or greater incline. Step on to the Belt while it is
moving and walk for 4 to 5 minutes.
Maximum speed reduced Striding Belt, Deck Malfunction
•Deck laminate is worn
through
•Belt worn
Replace Striding Belt and Deck
Line Voltage too low Plug the Treadmill into a power source with the
proper electrical requirements.
Striding Belt slips Adjust Striding Belt Tension (See “How To...”)
Drive Motor Belt slipping See “How To...Remove and Replace the Drive
Motor Belt” for proper Drive Motor Belt
tensioning instructions.
Striding belt comes in
contact with End Caps Unit is not level Adjust rear leveling legs (See Operation Manual)
Striding Belt needs to be re-
tensioned Adjust Striding Belt Tension (See “How To...”)
Missing rubber spacer Replace rubber spacer between Frame and
End Cap
End Cap(s) distorted Replace End Cap(s)
Striding Belt stretched or too
long Replace Deck and Striding Belt

5
Life Fitness Model 3500 Treadmill
TROUBLESHOOTING GUIDE
Symptom: UNIT RESETS RANDOMLY
Malfunction Probable Cause Corrective Action
Unit Resets Randomly Insufficient Power Source Plug Treadmill into power source with proper
electrical requirements. (See Operational
Manual)
Damaged Line Cord Replace Line Cord.
Line Cord improperly seated in
electrical outlet Secure connection at electrical outlet.
Low AC line voltage Too many items tied into AC line. Locate less
used circuit line outlet.

6
Life Fitness Model 3500 Treadmill
TROUBLESHOOTING GUIDE
Symptom: DISPLAY DOES NOT ILLUMINATE OR RESPOND TO INPUT
Malfunction Probable Cause Corrective Action
Display will not illuminate
when machine is turned on. Insufficient power source. Plug Treadmill into power source with proper electrical requirements. (See Operation
Manual)
Loose connection at Display
Console or Control Board. Secure connections at Display Console and Control Board.
Faulty Control Board. With a volt meter check cable voltage at P1
(Console cable) for 8v DC. (pin #2 positive ) (pin
#8 negative).
Faulty Display Console. Replace Display Console.

7
Life Fitness Model 3500 Treadmill
TROUBLESHOOTING GUIDE
Symptom: UNIT WILL NOT ELEVATE
Malfunction Probable Cause Corrective Action
Unit will not elevate Line Cord is crossed over lifting
assembly Check position of Line Cord placement.
Faulty Lift Actuator Perform Lift Test (See Diagnostics).
Defective Lift Actuator Replace Lift Actuator
Faulty Control Board Replace Control Board
Unit jammed at top of
elevation Faulty Home Switch Perform Lift Home Switch Test
Defective Home Switch Replace Home Switch
Faulty Control Board Replace Control Board

8
Life Fitness Model 3500 Treadmill
TROUBLESHOOTING GUIDE
Symptom: ERROR DISPLAY MESSAGES
Malfunction Probable Cause Corrective Action
ERROR MESSAGES:
START
(Occurs when the Striding Belt,
upon start up, will speed up at a
high rate)
Bad connection to Opto Speed
Sensor Check all electrical connections.
Misaligned or damaged Opto
Speed Sensor Adjust or replace Opto Speed Sensor.
RUN
(Occurs at sudden change in
Striding Belt Speed)
Moving Striding Belt was
suddenly stopped Reset machine by turning power OFF and ON at ON/OFF switch.
Bad connection to Opto Speed
Sensor Check all electrical connections.
Misaligned or damaged Opto
Speed Sensor Adjust or replace Opto Speed Sensor.
BELT
(Occurs at interruption in power
or when machine is just plugged
in))
Spike or interruption in power Reset machine by turning power OFF and ON at ON/OFF
switch.
Bad connection or damaged Line
Cord Check all electrical connections or replace Line Cord.
Faulty ON/OFF switch Replace switch.
Damaged Motor Controller Replace Motor Controller.
SPEED
(Striding Belt moving faster than
commanded)
Faulty Heatsink Control Board Replace Heatsink Control Board
NO-ZX Crimped Cable Replace bad Cables
Faulty Display Console Replace Display Console
Faulty Heatsink Control Board Replace Heatsink Control Board

9
Life Fitness Model 3500 Treadmill
TROUBLESHOOTING GUIDE
Symptom: HEARTRATE DOES NOT RESPOND
( IF EQUIPPED WITH OPTIONAL HEART RATE KIT )
Malfunction Probable Cause Corrective Action
Heartrate system does not
respond Heartrate cable not connected Check all electrical connections.
Loose connection at Console Secure connection at Console and Handlebar.
User may have an unusual heart
condition Have different people try Transmitter (chest) strap.
Faulty Transmitter and Receiver
(Heartrate kit) Replace Transmitter and Receiver (Heartrate kit).
Faulty Display Console Replace Display Console.
Outside noise (Cross talk) Move unit to another location.

10
Life Fitness Model 3500 Treadmill
NOTES:

1
Life Fitness Model 3500 Treadmill
DIAGNOSTIC TESTS
This Section describes the test procedures for the Life Fitness 3500 Treadmill Display Console Board including the
Heart Rate feature (operational only if equipped with the optional Heart Rate Kit Tray).
Diagnostic procedures will test the Display Console Board as used in the final Treadmill assembly. These procedures
will insure proper functioning of the Console LED’s, Keys and Displays as well as identify the Console version.
Begin with the Treadmill turned OFF. Hold the designated key during power up to enter into the chosen Diagnostic
Menu.
Continued
PURPOSE:
SCOPE:
PROCEDURE:

2
Life Fitness Model 3500 Treadmill
DIAGNOSTIC TESTS ( Continued )
THE SPEED DOWN KEY tIS USED FOR THE FOLLOWING TESTING INFORMATION:
⇒CHECK THE DISPLAY/KEYPAD FUNCTIONS
⇒REVIEW STATISTICS
⇒IDENTIFY SOFTWARE VERSION
USE THE ENTER KEY TO ADVANCE THROUGH THE TEST.
POWER UP THE UNIT WHILE HOLDING THE SPEED DOWN tKEY. ALL LED’s ON THE DISPLAY CONSOLE
WILL LIGHT. PRESS ENTER ONCE AND THE CONSOLE WILL BEGIN TO SCROLL THROUGH LIGHTING LED’s
INDIVIDUALLY.
PRESS ENTER A SECOND TIME AND THIS WILL BRING YOU TO THE KEYPAD TEST. BY PRESSING EACH OF
THE SIX KEYS, A PATTERN OF LED’s WILL LIGHT. THIS VERIFIES THAT EACH OF THE KEYS IS RESPONDING
AS INTENDED.
PRESS ENTER A THIRD TIME AND THE WORD “STATS” WILL APPEAR IN THE DISPLAY READOUT. PRESSING
THE SPEED sKEY WILL SCROLL YOU THROUGH THE INDIVIDUAL STATISTICS. (TO SCROLL BACK THROUGH
THE STATISTICS, PRESS THE SPEED tKEY).
1ST PRESS DISTANCE LED LIT: MILES ( IN HUNDREDS)
2ND PRESS TIME LED LIT: MOTOR ON TIME (IN SECONDS)
3RD PRESS INCLINE LED LIT: LIFT MOTOR RUN TIME (1/8 OF A SECOND)
4TH PRESS CAL/HR LED LIT: PERCENTAGE OF ELEVATION AND TIME
(percentage of elevation usage)
5TH PRESS SPEED LED LIT: CURRENT LIMITER ACTIVATION
PRESS ENTER A FOURTH TIME AND THIS WILL GIVE YOU THE SOFTWARE VERSION OF THE TREADMILL.
FOR EXAMPLE, THE DISPLAY READS 1. 5EE1 TRANSLATES TO:
1. 5 SOFTWARE VERSION
E ENGLISH MEASUREMENT (MILES)
E ENGLISH LANGUAGE
1120V
PRESS ENTER A FIFTH TIME AND “UNITS” APPEARS IN THE DISPLAY READOUT. PRESSING THE SPEED ∆
KEY WILL CHANGE THE UNIT OF MEASURE FROM ENGLISH TO METRIC (CODE VERSION 1.3 OR GREATER).
PRESS ENTER A SIXTH TIME AND “LANG” APPEARS IN THE DISPLAY READOUT. PRESSING THE SPEED ∆
KEY ENABLES YOU TO CHANGE FROM ENGLISH TO A FOREIGN LANGUAGE (CODE VERSION 1.3 OR
GREATER).
YOU CAN GO BACK TO THE START AT ANY TIME IN THIS TEST MODE BY PRESSING THE CLEAR/PAUSE KEY.
Continued

3
Life Fitness Model 3500 Treadmill
DIAGNOSTIC TESTS (Continued)
THE INCLINE DOWN tKEY IS USED FOR THE FOLLOWING TESTING INFORMATION:
⇒ELEVATION TEST/ HOME SWITCH
⇒SPEED MODE OPERATION
⇒HEARTRATE MODE OPERATION (IF EQUIPPED WITH OPTIONAL HEART RATE KIT)
POWER UP THE UNIT WHILE HOLDING DOWN THE INCLINE DOWN tKEY. THE DISPLAY CONSOLE WILL
READ TEST MODE. UPON INITIAL ENTRY INTO THE TEST MODE, THE LEFT COLUMN OF THE PROGRAM
PROFILE WINDOW WILL HAVE ONE TO TWO LED’s LIT.
THE FIRST THREE LED’s (FROM THE TOP) OF THE LEFT COLUMN ARE RELATED TO JUMPERS WHICH ARE
NOT APPLICABLE TO ANY OF THE TEST MODES.
THE FOURTH LED FROM THE TOP INDICATES THE CONDITION OF THE OPTO SPEED SENSOR. WHEN LIT,
THE OPTO SPEED SENSOR IS READING THROUGH A SLOT IN THE CHOPPER WHEEL THAT IS MOUNTED ON
THE MOTOR. WHEN THE LED IS OFF, THE OPTO SPEED SENSOR IS BEING BLOCKED BY A SLOT ON THE
CHOPPER WHEEL. NORMAL FUNCTION OF THE LED IS THAT IT FLASHES ON AND OFF AS THE DRIVE
MOTOR TURNS DURING OPERATION.
THE FIFTH LED FROM THE TOP WILL INFORM YOU IF THE UNIT IS A 120V OR A 220V UNIT. WHEN THE LED IS
OFF, THE UNIT IS 110V. WHEN THE LED IS ON, THE UNIT IS 220V.
THE SIXTH LED FROM THE TOP INDICATES THE ELEVATION (HOME SWITCH). WHEN THE LED IS OFF, THE
HOME SWITCH IS ENGAGED AND THE UNIT IS AT ZERO ELEVATION. WHEN THE LED IS LIT, THE HOME
SWITCH IS DISENGAGED AND THE UNIT IS AT A NON-ZERO ELEVATION.
THE BOTTOM LED IS THE EMERGENCY STOP SWITCH CONDITION. WHEN LED IS LIT, THE EMERGENCY
STOP SWITCH IS ENGAGED AND THE UNIT OPERATES. WHEN THE LED IS OFF, THE EMERGENCY STOP
SWITCH IS DISENGAGED AND THE UNIT WILL NOT RUN.
TO TEST THE ELEVATION:
CODE VERSION 1.7 OR LESS:
PRESS THE INCLINE UP sKEY TWICE TO SET THE DISPLAY AT 1%. THE UNIT WILL INCLINE UNTIL THE
INTERNAL UP LIMIT SWITCH IS ACTIVATED. THE UNIT WILL STOP, OR HOLD ITS’ ELEVATION, AT ANY POINT
IN THE INCLINE BY PRESSING THE INCLINE DOWN tKEY AND SETTING THE DISPLAY AT 0.5%. PRESSING
THE INCLINE DOWN tAND SETTING THE DISPLAY TO 0% WILL LOWER THE INCLINE UNTIL THE INTERNAL
LIMIT SWITCH IS ACTIVATED.
CODE VERSION 1.8 OR GREATER:
PRESS THE INCLINE UP sKEY TO ELEVATE THE TREADMILL. PRESS THE INCLINE DOWN tKEY TO LOWER
THE UNIT. A BEEPING WILL OCCUR WHILE THE UNIT IS BEING LOWERED AND THE HOME SWITCH IS
ACTIVATED.
TO COMPLETELY LOWER THE ELEVATION, SET THE INCLINE TO 0%. THE UNIT WILL CONTINUE TO LOWER
ITS ELEVATION UNTIL THE HOME SWITCH OR INTERNAL LIMIT SWITCH IS ENGAGED.
Continued

4
Lifestride Model 3500 Treadmill
DIAGNOSTIC MODE ENTRY (Continued)
SPEED MODE
PRESS ANY SPEED KEY TO ENTER THE SPEED MODE. THE DISPLAY WILL PRESENT TWO NUMBERS. THE
LEFT SIDE NUMBER REPRESENTS THE ACTUAL SPEED. THE RIGHT SIDE NUMBER REPRESENTS THE
RELATIVE POWER APPLIED TO THE MOTOR. THE UNIT WILL SUPPLY A FIXED AMOUNT OF POWER TO THE
DRIVE MOTOR IN THE SPEED MODE.
HEART RATE MODE (IF EQUIPPED WITH OPTIONAL HEART RATE KIT)
THE USER MUST HAVE THE HEART RATE TRANSMITTER AND RECEIVER ATTACHED IN THEIR PROPER
POSITIONS FOR THE HEART RATE TO DISPLAY. BY PRESSING ENTER, THE USERS HEART RATE WILL
APPEAR ON THE DISPLAY’S READOUT.
INCLINE UP sKEY
POWER UP THE UNIT WHILE HOLDING DOWN THE INCLINE sUP KEY.
THE STRIDING BELT WILL BEGIN TO MOVE AT .5 MPH. GRASP THE HANDLEBAR AND BEGIN WALKING ON
THE STRIDING BELT. WALK FORWARD TAKING THE SMALLEST STEPS POSSIBLE. THIS TEST WILL INDICATE
THE POWER DRAW ON THE TREADMILL. THE AVERAGE AMOUNT IS 8 TO 12 AND WILL VARY ACCORDING
TO THE TECHNICIANS WEIGHT. EXCESSIVELY HIGH NUMBERS INDICATE A NEWER, NON-BROKEN IN
STRIDING BELT OR A VERY OLD, WORN BELT.
NOTE: DO NOT STAND ON THE STRIDING BELT DURING POWER UP.

1
Life Fitness Model 3500 Treadmill
How To ... REMOVE AND REPLACE THE VENT COVER
Tools Required: Phillips Screwdriver
Step 1
Turn the power OFF at the ON/OFF switch and then unplug the unit from the electrical outlet.
Step 2
Use a phillips screwdriver to remove the two SCREWS securing the sides of the VENT COVER to the MOTOR
COVER.
Step 3
Grasp the VENT COVER in the center and pull away from the MOTOR COVER to disengage the two snap down
CLIPS located on the inside, center of the VENT COVER.
Step 4
Position the new VENT COVER into place and reverse steps 1through 3to return all parts to their proper locations.

2
Life Fitness Model 3500 Treadmill
How To ... REMOVE AND REPLACE MOTOR COVER
Tools Required: Phillips Screwdriver, hex key wrench set
Step 1
Turn the power OFF at the ON/OFF switch and then unplug the unit from the electrical outlet.
Step 2
Remove the VENT COVER (See “How To...”).
Step 3
Use a phillips screwdriver to remove the SCREW securing the RETAINING PLATE and FIBERBOARD WEDGE in
place on the MONOCOLUMN.
Step 4
Remove the four SCREWS securing the MOTOR COVER in place against the Treadmill FRAME. Lift the MOTOR
COVER from the machine.
Step 5
Place the new MOTOR COVER in position and reverse Steps 1through 4 to return all parts to their proper locations.