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Service Manual
AMT12 Base
Open Stride and Fixed Stride
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Contents
1 - Introduction ......................................................................................................................... 7
About this Document ...................................................................................................................... 7
General Information........................................................................................................................ 8
Right, Left, Front, and Back Conventions .......................................................................... 8
General System Information ................................................................................................ 8
General Information .............................................................................................................. 8
Tools Required ......................................................................................................................... 8
4 - 6 gear puller .............................................................................................................................. 8
Safety Guidelines ........................................................................................................................... 8
Operating Safety ............................................................................................................................ 9
2- Operation Verification....................................................................................................... 11
Verification Procedure ..................................................................................................................11
Verification Checklist ....................................................................................................................12
3- Standardized Service Access Codes ................................................................................. 13
Accessing the Service Software ...................................................................................................13
P20 Service Software Access ............................................................................................. 14
Entering the Service Software on a P80 console ........................................................... 15
Hardware Validation = Diagnostic Tests (51765761) ..................................................................16
Club Parameter = Settings (5651565) .........................................................................................17
Information Display (65) ...............................................................................................................18
4- Theory of Operation .......................................................................................................... 19
Console Models ............................................................................................................................19
Basic operation of a console ........................................................................................................20
AMT Base Operation ....................................................................................................................22
Power Generation ................................................................................................................ 22
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Lower Electronics Module .................................................................................................. 22
DC Power Distribution: ......................................................................................................... 22
A regulated 14.5VDC power supply charges the 12V battery. .................................. 22
AMT Resistance Control: ..................................................................................................... 23
Vertical Resistance: ............................................................................................................. 23
Horizontal Resistance: .......................................................................................................... 24
AMT motion detection (RPM): ........................................................................................... 24
DC Lift System – Position Monitoring (If Equipped .......................................................... 27
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5- Troubleshooting Procedures ............................................................................................. 28
Introduction ...................................................................................................................................28
Troubleshooting Generated Power ..............................................................................................29
Measuring the Resistance of a Generator ...................................................................................30
Upper Display does not illuminate ................................................................................................31
Standardized Error Codes ............................................................................................................33
Validating the Reported Failure ....................................................................................................34
Troubleshooting Control Error Codes ..........................................................................................35
Error 05 - Key Depressed at Power Up ........................................................................................35
Error 09 - Lower PCA Memory Test Errors ..................................................................................37
Error 12 - Watchdog (Lower PCA) ...............................................................................................37
Error 80, 81, 82, & 83 – P30 Machine Controls Not Working ......................................................38
Troubleshooting the Brake System ..............................................................................................39
Troubleshooting the Lift System ...................................................................................................40
Error 40 - No Lift Motion Detected ...............................................................................................41
Error 42 - Lift Position Value Out of Range ..................................................................................43
Error 44 - Un-commanded Lift Motion ..........................................................................................45
Error 45 - Lift Moving in Wrong Direction .....................................................................................46
Error 46 – Low Battery Voltage (Open Stride AMT12 only) .........................................................47
Troubleshooting Communications ................................................................................................48
Errors 30, 31, 32 and 33 - Communications Error .......................................................................48
Event 70 - 79 ................................................................................................................................49
Troubleshooting Heart Rate Issues: .............................................................................................50
Wireless Heart Rate Does Not Work ............................................................................................51
6- Replacement Procedures ................................................................................................... 53
Cover Replacement......................................................................................................................54
Replacing a Belt Guard ................................................................................................................65
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Replacing the Upper Arm Grip .....................................................................................................69
Replacing a Flat Belt Terminal .....................................................................................................74
Replacing a Upper Arm Flat Belt Pulley .......................................................................................80
Replacing a Stairarm Pedal .........................................................................................................85
Replacing a Stairarm ....................................................................................................................87
Replacing the Flat Belts ...............................................................................................................93
Inside Flat Belt Replacement .......................................................................................................97
Outside Flat Belt Replacement ..................................................................................................106
Replacing the Front Arm Assemblies - With Flat Belts and Press Fit Cams (After 4/3/2013) ...122
Replacing the Lower Board ........................................................................................................163
Replacing the Lower PCA and Battery Bracket .........................................................................164
Replacing the Battery .................................................................................................................166
Replacing the Generator Belt .....................................................................................................167
Replacing the Generator ............................................................................................................169
Replacing the Drive Input Pulley Belt .........................................................................................171
Replacing the Step Up Pulley ....................................................................................................172
Replacing the Crank Arm ...........................................................................................................175
Replacing the Drive Input Pulley ................................................................................................178
Replacing the Lift Arm Housing ..................................................................................................185
Replacing the drive input housing ..............................................................................................202
Replacing a Tie Rod ...................................................................................................................222
Replacing the H-Brake Belt ........................................................................................................225
Replacing the H-Brake Drum Assembly.....................................................................................233
Replacing the Gas Shock ...........................................................................................................242
Replacing the Incline Motor ........................................................................................................245
7 – Adjustment Procedure ................................................................................................... 251
Measuring the Resistance of a Generator .................................................................................251
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Inspecting and Adjusting the H-brake Belt Tension ...................................................................252
Inspecting and Adjusting the Generator Belt Tension ................................................................255
Inspecting and Adjusting the Drive Input Belt Tension ..............................................................257
Calibrating the Incline Motor ......................................................................................................263
Drive Belt Gauge Instructions ....................................................................................................265
8- Preventative Maintenance ............................................................................................... 267
9- Wiring & Block Diagrams............................................................................................... 269
P30 - AMT '11 835 Block Diagram .............................................................................................269
P20_P30_P80 AMT '11 Wiring Diagram ....................................................................................269
10 – Exploded View .............................................................................................................. 271
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1 - Introduction
In This Section
About This Document .......................................................................
Right, Left, Front, and Back Conventions .......................................
General System Information .............................................................
General Information ..........................................................................
Tools Required ..................................................................................
Warning and Caution Statements and General Safety Guidelines
Safety .................................................................................................
About this Document
Warning: This service manual is for use by Precor trained service providers only.
If you are not a Precor Trained Servicer, you must not attempt to service any Precor Product; 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.
Manual Number: 20039-172 rev A02
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General Information
Multimeter
US and metric end wrench set
Allen wrench set
US and metric socket wrench set
Anti-static kit
Torque wrench, 200 in./lbs.
Screwdriver set
Torque wrench, 200 ft./lbs
OTC 6673 Universal Belt Tension Gauge
4 - 6 gear puller
Right, Left, Front, and Back Conventions
In this manual, right, left, front, and back are from the perspective of a user standing on the AMT facing the
console display.
FIGURE 1: FRONT, BACK, LEFT, RIGHT CONVENTIONS
General System Information
The generator performs three functions in the AMT. First, by controlling the amount of electrical current
applied from the generator to a load circuit, the user’s pedaling resistance is controlled. Second, the
generator is used to charge the AMT’s internal battery. Lastly, one of the generators three phase output
windings is monitored to determine when the unit is in use and when it is idle. This system also determines
the step rate by determining the operating speed (output frequency) of the monitored generator winding. A
magnetic brake applies resistance to horizontal motion and a sensor that measures horizontal motion (stride
length).
General Information
For the latest exploded view, part number and part pricing information, visit the Precor dealer website at
www.precor.com/connection.
Tools Required
Safety Guidelines
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Warning statements indicate a particularly dangerous activity. Warning statements you will find in this
manual include:
Because this is a self powered unit, it will either be necessary to either equip the unit with the optional
external power supply or have an assistant pedal on the unit while voltage measurements are being
taken. Because of the danger of working on the unit while it is in motion using the optional external
power supply is strongly recommended.
When the unit is used, stairarms are in motion; the generator will operate and produce potentially
hazardous voltages even when the battery is disconnected.
Caution statements are intended to prevent damage to the AMT as a result of the current activity.
Caution statements included in this manual are listed below:
When it is necessary to lift or move the AMT, ensure that the AMT has adequate support and that
you use proper lifting techniques. When the rear platform is removed, the AMT may be lifted from
the rear and moved like a wheelbarrow.
To remove power from the AMT, the optional external power supply (when equipped) must be
disconnected from the wall outlet and the red (positive) wire must be disconnected from the battery.
Always ensure that the AMT external power supply is unplugged from the wall outlet and the red
(positive) wire is removed from the battery when you inspect or adjust the AMT, or when you isolate,
remove, or replace an AMT component.
Removing the covers exposes high voltage components and potentially dangerous machinery.
Exercise extreme caution when you perform maintenance procedures with the cover(s) removed.
During service operations you will be very close to moving machinery and voltage bearing
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 AMT operation.
A pinching hazard exists when the unit is operated. It is possible to seriously pinch a finger. The
AMT can be mechanically locked by inserting a screwdriver through the primary sheave and frame.
See the illustration below. Locking the AMT will prevent accidental pinching.
A pinching hazard exists when the unit is operated. It is possible to seriously pinch a finger. The
AMT can be made immobile by lift the stairarm pedals and removing the tension from stairarm flat
belts. Removing the tension from the flat belts will prevent accidental pinching.
Operating Safety
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Safety guidelines you should know and follow include:
Read the owner’s manual and follow all operating instructions.
Operate the AMT on a solid, level surface with the unit properly leveled. The AMT is properly leveled
when all five feet are in contact with the floor. Visually check the AMT 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 AMT.
When operating the AMT, 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 AMT, while performing service.
To prevent electrical shock, keep all electrical components away from water and other liquids.
Do not use accessory attachments that are not recommended by the manufacturer-such attachments
might cause injuries.
AMT’s equipped with Cardio Theater PVS units will have external power supply and coaxial cable routed
through the bottom of the unit to the top of the display console. Cord management must be maintained.
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2- Operation Verification
This section provides you with a quick method of checking the AMT operation. Check the AMT operation at
the end of a maintenance procedure and when it is necessary to ensure that the AMT is operating properly.
Verification Procedure
1 Pedal the AMT to apply power, or use the optional external power supply.
2 Press and hold the reset key for at least 6 seconds, if errors are present the error log will be displayed.
Make note of all the errors in the error log and odometer reading for which the error occurred. The
odometer in the error log can help you determine age and relevance of the error. Once the errors have
been written down, the error log can be cleared.
3 Enter the Hardware Validation test by entering Diagnostic mode as follows:
Press either the STOP, PAUSE or RESET buttons and then enter 5,1,7,6,5,7,6,1
Select and run the Display Test, then the Keypad Test, then the Heart Rate Test and verify
results. (LEDs light, Keys all function, Heart rate is acquired and displayed)
Enter the Machine Tests (submenu) and run the Brake test and the Incline test and verify results.
(Resistance is smooth and is controlled from resistance level 1 to resistance level 20, Lift (if
applicable) goes up and down and the A/D value changes smoothly throughout the range)
Press the reset or back key to exit diagnostics.
4 Operate the AMT in the Manual program. Adjust the resistance to level 7. Operate the AMT for at least
1 minute while pedaling the unit.
a) Concentrate on the feel of the motion and the sound of the input drive assembly. Be on the alert for
unusual noises or vibrations.
b) Observe the LED’s on the electronic console. Make sure that each LED lights as the information
corresponding to that LED is displayed on the electronic console.
5 If the unit is equipped with a variable step height (Open Stride), press the INCLINE key while viewing
the electronic console. Pedal the unit and confirm that the step height increases and the incline display
increments to level 5 as the INCLINE key is continually being pressed.
6 If the unit is equipped with a variable step height (Open Stride), press the INCLINE key while viewing
the electronic console. Pedal the unit and confirm that the step height increases and the incline display
decrements to level 1 as the INCLINE key is pressed.
7 Press and hold the reset key for at least 6 seconds, to look at the error log again. This time look for any
NEW errors displayed resulting from the verification test indicating that the unit needs attention.
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Verification Checklist
Operation Verification Checklist
If errors are present in the error log, make note of those errors and clear the error log.
All LEDs function properly during the “Hardware Validation” Tests.
All keys on the keypad function properly during the “Hardware Validation” Tests.
Heart rate functions normally and displays a valid heart rate.
Input drive system functions properly throughout the minimum to maximum resistance range. All drive
system components (belts, pulleys, lower control module) free of excessive noise, vibrations, or
smells
Incline (if equipped) A/D value increments and decrements smoothly throughout the incline range.
Incline operates within the complete range of lift when the “UP” or “DOWN” keys are pressed, and are
free of excessive noise or vibrations.
No new errors were logged in the error log.
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3- Standardized Service Access Codes
Access Code
Heading Name
Function
51765761
Hardware
Validation
Running
Diagnostic
Tests
5651565
Club Parameters
(Commercial)
Changing
Machine and/or
Workout
Parameters
65
Information
Display
Acquiring
Information
These standardized service access codes that are followed by all consoles (Standard, P10, P20, P30) are
split into 3 functional modes, “Hardware Validation”, “Club Parameters”, and “Information Display”.
“Hardware Validation” is a set of functional diagnostic tests that are useful in
troubleshooting problems as well as verifying proper operation.
“Club Parameters” are sometimes referred to as “Club Settings”, and are used to manage
usage of the machine.
“Information Display” is used to access information such as the odometer, software
versions, and error logs.
Accessing the Service Software
Accessing these 3 areas are accomplished the same on all consoles (Standard, P10, P20, P30) except
P80. You must first press either “STOP”, “PAUSE”, or “RESET” key (whichever is available on your
specific console) followed by a numeric code for the area of service software you wish to access. The
standard access codes use sequential key presses, not simultaneous key hold downs. The allowable delay
between key presses is short. If too much time is taken between key presses or the wrong key is pressed
the access procedure will be aborted. If the access is aborted, it will be necessary to start over from the
beginning.
The codes are as follows;
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On the “Standard”, “P10”, and “P30” consoles these codes are entered via a direct access 10-key pad. The
“P20” has a slightly more challenging method of entry.
P20 Service Software Access
The P20 will start with stop, pause, or reset, numeric values have been assigned to the function keys in the
absence of the 10-key pad.
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Entering the Service Software on a P80 console
Procedure:
1. The Welcome screen will be the first screen you see when you approach the P80 console. Press
the Pause button and continue holding it down while you double press (prior to version 1.1
software release) or single press (version 1.1 or after software release) in sequential order an X
configuration on the Volume and Channel key pad ( Channel Up, Volume Down, Volume
Up, Channel Down). See Diagram 8. Release the Pause button when done pressing the arrows.
Note: The keypad X configuration sequence should not be faster than 1 second between
each key stroke. Any speed faster than 1 second may result in an unsuccessful access to the
sign-in screen.
Diagram 8
2. The sign-in screen will be displayed. Type in the technician access code (5,1,7,6,5,7,6,1) and press
OK.
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Hardware Validation = Diagnostic Tests (51765761)
Diagnostic Test
Performed
Console Function or
Base Function
Test Description
Display Test
Console Function Test
While in this test, each time the “OK” key is
pressed a different group of LEDs will
illuminate. Press the back button to exit this
test.
Keypad Test
Console Function Test
While in this test, a map of the keys will be
displayed. When a key is pressed, the
corresponding LED will extinguish. When
finished, press and hold the “BACK” button
to exit the test.
Heart Rate Test
Console Function Test
While in this test, unfiltered, filtered, and
pulse values will be displayed. Use a Polar
heart rate simulator to test the wireless
heart rate. Grasp the grips to test the hand
held heart rate. Press the back button to exit
this test.
Brake Test
Base Function Test
Brake power bits information will be
displayed. Use this test to determine
resistance related problems. Press the back
button to exit this test.
RPM Test
Base Function Test
Pulse is displayed, showing a count of zero
crossings from the generator. RPM shows a
software averaged version of “Pulse”, and is
displayed in user mode as stride count. Use
this test to determine stride count related
problems. Press the back button to exit this
test.
Battery Test
Base Function Test
Displays battery voltage. Use this test to
determine the cause of low battery
warnings. Press the back button to exit this
test.
Stride Position Test
Base Function Test
Displays the output of the stride position
sensor. Press the back button to exit this
test.
Vertical Position Test
Base Function Test
Displays the output of the vertical position
sensor. Press the back button to exit this
test.
Stride Count Reset
Base Function Test
This is not a test, it resets the belt usage
counter after a belt replacement. Press the
back button to exit.
Crossramp Test
Base Function Test
Tests the lift motor functions of the
adjustable step height feature. Press the
back button to exit this test.
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Club Parameter
Setting
Parameter Description
Select Language
Sets the default language for ALL workouts on this machine.
Factory default is English. Language for single use workouts can
still be set by the user from the workout options.
Select Units
Sets units of measure (US standard or Metric). Factory default is
US standard.
Set Max Workout Time
Sets the maximum allowable workout time for each user. Factory
default is 60 minutes.
Set Max Pause Time
Sets the maximum time that the workout can be paused for.
Factory default is 120 seconds.
Set Max Cool Down Time
Sets the amount of time that a cool down period will occur at the
end of every workout. Factory default is 5 minutes.
Set Metrics Default
Sets a metric that may be of specific importance to the specific
facility or fitness trainer. The selected metric will scroll across the
screen at regular intervals during the workout. Factory default is
“NONE”
Club Parameter = Settings (5651565)
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Information Display (65)
Information
Displayed
Information Description
Belt Usage
Displays the total number of strides counted since the last stride count
reset. Also displays the total number of stride count resets performed on
this machine.
Odometer
Displays the total number of accumulated strides on the unit. This value
is stored on both the upper PCA in the console and on the lower PCA.
Odometer information is transferred between the upper and lower
boards when either of the boards has been changed or replaced.
Hours of Use
Displays the total number of hours that the unit took to accumulate those
miles unit. This value is stored in the upper PCA in the console, so if that
PCA is replaced the hours of use would start again from “0”
Upper Boot Software
Displays the current version of software that handles flash upgrades of
upper PCA (console) software.
Upper Base Software
Displays the current version of operating software loaded in the upper
PCA (console). This is the unit specific console software.
Lower Software
Displays the current version of software loaded in the lower control
module.
Metrics Board Software
Displays the current version of software loaded in the Metrics board.
Stride Dial Software
Displays the current version of software loaded in the Stride Dial board.
Serial Number
The base serial number can be set here using the WinCSAFE computer
software. Factory default is NONE.
Usage Log
Displays the Statistics of the workout programs used, the number of
times accessed, and duration of use.
Error Log
Displays a running log of errors encountered on the unit.
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4- Theory of Operation
Console Models
Consoles that could appear on the AMT12 Base
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Basic operation of a console
The purpose of this section is to describe the operation and maintenance of the AMT base, however
it would be difficult to talk about the base without referring to console controls. Basic console
functions that apply to all models of consoles are discussed. For specific details about a particular
model of console (P10, P20, P30, P80), please refer to that console manual.
All basic consoles provide user input (keypad functions), user display (LED display / user
feedback), automated control (heart rate program, interval program) and service software routines
(tests, settings, and information).
The keypad functions can vary between different console models, however the basic functions that
all consoles have are Quickstart, Incline (up or down) and Resistance (up or down).
The display features can vary between different console models, however the information conveyed
by those displays are very similar.
Service software routines are handled exactly the same for all console models. Entering into
“Hardware Validation” tests, “Club Parameter” settings, or “Information Display” is also the same
and are called “Standardized Service Access Codes”.
The service software and standard access codes are described in detail in the “Standardized
Service Access Codes”, section 5 of this manual.
There are also “Standard Error Codes” which all console models follow. For a full listing of
“Standard Error Codes” used for this model see “troubleshooting”, section 7 of this manual.
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The processor in the console provides user input, user display, and automated control to the
system, while the processor in the lower electronics module performs the actual machine function.
The two processors communicate via a serial data stream.
When the user makes a request of machine function to take place via the keypad (user input), the
console processor communicates that request to the processor in the lower electronics module via
the serial data stream.
Once the lower processor receives the request the lower control module performs the machine
tasks associated with the request. The console processor goes about its business of monitoring
keypad entry and providing display feedback.
The lower processor also provides status back to the console processor (via the serial data stream)
to report if everything occurred properly, or if an error code needs to be written to the error log.
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AMT Base Operation
Power Generation
The Commercial AMT base is powered by a 3-phase generator that spins when the user is pedaling
the stairarms. There are 3 wires in the cable coming from the windings of the generator, connected
to the lower control module via 3 individual spade style connectors. The frequency of the AC sine
waves is determined by how fast the user is pedaling, and the voltage level of each AC sine wave
is approximately 100VAC.
The generator performs three functions in the AMT. First, by providing power to the lower control
module. Second, the generator is used to charge the EFX’s internal battery. Lastly, one of the
generators six phase output windings is monitored to determine when the unit is in use and when
it is idle. This system also determines the stride rate by determining the operating speed (output
frequency) of the monitored generator winding.
Lower Electronics Module
The lower control module consists of an AC to DC conversion of the generator output, a distribution
of DC power supplies, a DC lift motor controller (only on open stride models), and control of workout
resistance.
DC Power Distribution:
Once the generator’s AC outputs are converted to DC, there are a number of regulated DC supplies
that power the various functions of the AMT. The first regulated DC power supply in the distribution
chain is an 18VDC supply, but only supplies this 18VDC if the user is pedaling the AMT. If the
customer wishes to add the external power option to the AMT, an external 18VDC supply replaces
the 18VDC supplied by generator power, allowing the unit to stay powered up (whether pedaling
or not).
A regulated 14.5VDC power supply charges the 12V battery.
A regulated 7.5VDC power supply is sent to the console via the data cable. The electronic circuits
in the console operate on +5V DC, however the lower control module sends +7.5V DC due to the
optional external equipment such as Fitlinxx, which may be connected to the CSAFE
(Communication Standard for All Fitness Equipment) port. By sending a higher voltage (+7.5V) and
regulating down to +5V DC, we insure that we can supply enough power to both the console and
the optional external equipment. To insure that this 7.5VDC regulated power supply is stable
enough to run all console related functions, the lower control module switches this 7.5VDC power
“ON” only after a rate of greater than 20RPM at the crankarms is detected.
A regulated 5VDC power supply and a regulated 3.3VDC power supply are used to power all the
digital logic functions of the lower control module.
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Lift Motor
J3-2
J3-3 J3-4 J3-5
J3-6
R
BK
BR
1K
Intermediate Connector
R
BK
W
F1
6.3 amp
LIFT
(If so
equipped)
AMT Resistance Control:
Vertical Resistance:
The Experience Line AMTs use a three phase AC generator, and all current being drawn
throughout the unit comes from this generator. The only other power supply in the unit is a variable
power supply, used to provide variable control of mechanical resistance, in this case (Magnetic
Force). The user selects the desired level of resistance at the console, and the console passes that
request along to the lower control module via the serial communication through the data cable. The
processor on the lower control module then adjusts the output of the variable supply to an
appropriate value to facilitate the user’s requested resistance level. That voltage is applied to an
eddy current magnet pointed at the flywheel of the generator, which then determines the amount
of braking force that is placed on the generator. The more voltage sent to the eddy current magnet
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the larger the magnetic braking force placed on the flywheel of the generator, thus providing
mechanical resistance.
The reason that Precor uses a 3-phase generator on a self-powered AMT while self-powered EFXs
use a 6-phase generator is centered in its use of Magnetic force as a resistance method.
Horizontal Resistance:
The AMT’s horizontal braking force is achieved through the use of a drum style eddy current brake
assembly. The inner drum of the assembly has a number of fixed magnets glued to outer
circumference of the drum. These fixed magnets are considered the primary magnetic field. The
outer drum of the assembly has a copper sleeve bonded to the inner circumference of the drum.
When the outer drum moves relative to the position of the inner drum, the fixed magnets induce a
current into the copper sleeve. The current now flowing in the copper sleeve will produce a
secondary field, which will in turn repel against the magnetic field of the fixed magnets.
AMT motion detection (RPM):
This diagram shows the 3 sine waves from the generator, which the LPCA uses to supply and
distribute power throughout the system. The LPCA also utilizes a “zero crossing detector” to
determine a stride count by counting the zero crossings from 1 of the 3 sine waves coming from
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the generator. The zero crossing counts the speed of the generator and the LPCA processor
divides out the step-up in the pulleys will determine the RPM at the cranks.
When the user begins to pedal the unit, The LPCA powers up right away. To insure that all regulated
supplies are up and stable, the unit holds power off of the UPCA until a minimum of 20 RPMs at
the crank is detected. Once this minimum speed is detected, the processor will turn on a relay,
which in turn switches power onto the UPCA. When the user presses “Quickstart” or goes into a
program, the UPCA is going to want to use the actual stride count for its user display functions.
The stride is counted by the LPCA processor, and transferred to the UPCA processor via the
communication cable.
DC Lift System – Motion Control (If Equipped)
The motor used in the lift system of a self-powered unit is a DC motor. It is powered by 12VDC
from the battery, and utilizes a 7 amp self-resetting fuse on the lower control module to protect the
switching circuitry on the lower control module. Motion can be driven in 2 different directions by
switching the polarity of the battery voltage applied to the windings of the motor. Since the lift motor
is only expected to travel at one speed, the voltage is NOT varied. A single voltage is switched to
the lift motor to initiate motion, and the polarity is switched to control direction.
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When the user presses the “UP” button on the console and the console passes that request along
to the lower control module via the serial communication through the data cable. The processor on
the lower control module then switches the 12VDC battery voltage to the lift motor windings as a
POSITIVE 12VDC.
When the user presses the “DOWN” button on the console and the console passes that request
along to the lower control module via the serial communication through the data cable. The
processor on the lower control module then switches the 12VDC battery voltage to the lift motor
windings as a NEGATIVE 12VDC.
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DC Lift System – Position Monitoring (If Equipped)
The unit also requires an absolute measurement of lift position. This is achieved through the use
of a potentiometer. The potentiometer is turned by being geared to the motor, which changes the
wiper resistance.
With +3.3V DC applied across the potentiometer, the center wiper connection will be a variable
voltage (between 0 and +3.3V DC), dependent on the position of the lift. This variable voltage is
applied to the input of an 8-bit A/D converter, which converts the analog voltage into an 8-bit binary
numeric representation that the processor can understand.
As the voltage returned by the potentiometer changes between 0 and 3.3V DC, the corresponding
A/D values change between 0 and 255. In this way, the processor can keep track of where in the
lift range the lift is truly positioned.
It is important to note that since the potentiometer is mechanically connected to the gearing of the
motor, it would be highly unlikely (if not, impossible) for a lift motor to go out of calibration without
having some damage that needs to be repaired. See the section on troubleshooting the lift system
if this occurs.
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5- Troubleshooting Procedures
In This Section
Introduction
Troubleshooting Generated Power
Troubleshooting No Power To The Console
Standardized Error Codes
Validating The Reported Failure
Troubleshooting Control Error Codes
Troubleshooting the Brake System
Troubleshooting the Lift System
Troubleshooting Communications Errors
Odometer Tracking & Flat Belt Replacement Event Codes
Troubleshooting Heart Rate Issues
This section contains troubleshooting procedures and presents a methodology for identifying and isolating system
issues. Not all system issues will create an error code condition so the approach is to identify and verify the stated
problem and then use the systems own self tests to help isolate the problem. In many cases, that will include the
use of error codes, but not always.
Introduction
The customer has reported a failed condition. The failure that is reported may differ from your observations
as a trained technician. That is why it is important to validate the reported failure. The first step in this
investigative troubleshooting methodology is to first identify the current overall operating condition of the
treadmill. Is it operational or not.
If the AMT does not turn on or the console will not illuminate:
Follow the appropriate procedure for “Troubleshooting Generated Power” or “Troubleshooting No
Power to the Console”.
If the system powers up and can be at least partially operated:
Follow the procedure below – “Validating the Reported Failure”.
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Troubleshooting Generated Power
The generator performs three functions in the AMT. First, by controlling the amount of electrical load applied
to the generator, the user’s pedaling resistance is controlled. Second, the generator is used to charge the
AMT’s internal battery. Lastly, one of the generators three phase output windings is monitored to determine
when the unit is in use and when it is idle. This system also determines the stride rate by determining the
operating speed (output frequency) of the monitored generator winding.
WARNING:
Before continuing with this procedure, review the Warning and Caution statements listed in the Warning and
Caution Statements and General Safety Guidelines Section, Things You Should Know.
Because this is a self-powered unit, it will be necessary to equip the unit with the optional external power supply
or have an assistant pedal the unit while voltage measurements are being taken. Because of the danger of working
on the unit while it is in motion, using the optional external power supply is strongly recommended.
Perform the generator resistance test per Procedure XX. If any of the resistance measurements are
significantly high or significantly low, replace the generator.
The following voltage reading must be taken while the unit is in motion. Extreme care must be taken to keep
meter leads, hands, etc. clear of all moving parts. Using an AC voltmeter, measure the voltage between 1
& 2, 2 & 3, and 1 & 3 on J1 of the lower PCA. All AC voltage readings will vary depending on the unit’s
stride rate at the time the measurement is taken. At a stride rate of 100 strides per minute, all three voltage
readings will be approximately 100 VAC -110 VAC.
If any of the three readings in step 2 are significantly low, replace the generator.
If you have performed all of the above tests and are unable to resolve the problem, contact Precor customer
support.
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Measuring the Resistance of a Generator
Caution
If an external power supply is connected to the EFX, disconnect the external power supply from the EFX
before continuing with this procedure. Before continuing with this procedure, review the Warning and
Caution statements listed in Section One, Things You Should Know.
Procedure
Remove the red battery lead from the lower PCA. See Diagram 10.3.1
Set the ohmmeter to a range that will conveniently read up to 50 .
Remove the three-phase generator connector from the lower PCA; refer to Diagram 8.1.1, below.
With an ohmmeter, read between terminals 1 & 2, terminals 2 & 3, and terminals 1 & 3 on the six phase
generator connector (J1). Each of the readings should be between 26 and 30 .
If any of the readings are significantly high or significantly low, remove the intermediate cable from the
generator and perform the same measurements as in step 4 on the generator connector. If the reading is
now correct check and or replace the intermediate cable. Refer to Diagram 8.1.1. If the readings are still
incorrect, remove and replace the generator per Procedure XX.
Reconnect the intermediate cable removed in step 5 to the replacement generator and the lower PCA.
Reconnect the red battery lead to terminal M6 of the lower PCA.
Diagram 8.1.1 Lower Control Module Connector Layout
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