SportsArt Fitness Upright Bike C520U Operating instructions

C520U/C531U Repair Manual

Table of Contents
1-1-1. Display Picture – C520/C531
1-2-1. Component Placement - C520U/C531U Display
1-2-2. Component Placement - C520U/C531U Lower Body
1-3-1. Block Diagram - C520U/C531U Electronics
1-4-1. Wire Connections - C520U/C531U Display
1-4-2. Wire Connections - C520U/C531U Drive Board
1-5-1. LED Indicators - C520U / C531U Display Board
1-5-2. LED Indicators - C520U/C531U Drive Board
1-6-1. C520U/C531U Display Specifications
2-1-1. Display Malfunction Troubleshooting Table - C520U/C531U
2-1-2. Display Malfunction Troubleshooting Table - C520U/C531U, Continued.
3-1-1. Malfunction: Unit will not start (alternator).
3-2-1. Malfunction: Unit will not start (battery).
3-3-1. Malfunction: No RPM value
3-4-1. Malfunction: No resistance
3-5-1. Malfunction: Resistance is heavy.
3-6-1. Malfunction: Telemetry heart rate malfunction.
3-7-1. Malfunction: HTR heart rate malfunction
4-1-1. Mechanical Maintenance Schedule - C531U/C520U
4-2-1. Mechanical Troubleshooting Chart - C520U/C531U.

1-1. Display Picture - C520U/C531U
1-1-1

1-2. Component Placement - C520U/C531U Display
1-2-1
HR telemetry
receiver board
HTR board
Display board

1-2. Component Placement - C520U/C531U Lower Body
1-2-2
Electro-
magnet
Drive
board
Flywheel with built-in
alternator
Battery
Reed switch

1-3. Block Diagram - C520U/C531U Electronics
1-3-1
Display
Board
Drive
Board
Electro-magnet
Reed switch
Battery
HTR board HR receiver
board
Sensor – L
Sensor – R
Alternator
Battery charger

1-4. Wire Connections - C520U/C531U Display
1-4-1
To HTR contact plates (left
and right)
LED1
Display power
supply
To drive board
To HTR
board
To HR
receiver
To display

1-4. Wire Connections - C520U/C531U Drive Board
1-4-2
To display board
To battery charger
To reed switchTo battery
To electro-magnet To alternator

1-5. LED Indicators - C520U / C531U Display Board
1-5-1
Power Indicator LED1
Lit indicates there is
incoming power.

1-5. LED Indicators - C520U/C531U Drive Board
1-5-2
Alternator fuse F1
Battery fuse F2
CLK Indicator
LED flashes when
pedals move.
Drive board power
Lit indicates there
is incoming power.
Battery charge
Lit indicates there
is incoming power to
recharge the battery.
Exterior battery charger
fuse F3

1-6. C520U/C531U Display Specifications
Specification Contents Notes
Power supply AC alternator
Backup power
supply
6.4 VA battery
Battery automatically recharges or can be recharged via an exterior
charger.
Resistance Electro-magnet
Speed detection
Reed switch
Resistance LEVEL 1 - LEVEL 20
Display method Segment array and numerical LEDs
Main window Dot matrix
Character
window
65% HR TARGET, Heart rate, 80% HR TARGET
WORKOUT LEVEL / CALORIES / TIME / RPM
DISTANCE / CAL/HR / WATTS / SPEED
Workout
programs INTERVAL / RANDOM / HILL / TRACK / ZONE TRAINER / CARDIO / WT LOSS
Heart rate
control programs
CARDIO, WT LOSS, ZONE TRAINER
Heart rate Telemetry heart rate detection
User IDs Four user IDs（USER1- USER4）
Motion Belt operated
1-6-1

2-1. Display Malfunction Troubleshooting Table - C520U/C531U
Malfunction
Circumstance Inspection and Test Points Suggested
Components Notes
Cannot
start unit The display is not lit; I pedal the
bike; but the
display still
doesn’t light.
1. Inspect cable connections.
2. Inspect drive board fuse.
3. Inspect drive board power LED.
4. Inspect the alternator.
1. drive board
fuse
2. drive board
3. alternator
Cannot
start unit When I don’t pedal the bike, the
display does not
light.
1. Inspect battery fuse on the drive board.
2. Measure battery voltage. Battery voltage should be 5.5V
or more.
3. If battery voltage is under 5.5V, pedal the unit at over 50
RPM to recharge the battery.
4. Replace the battery if voltage is under 2.0 and it won’t
recharge.
1. battery fuse
on the drive
board
2. battery
Display
won’t
operate
I start pedaling
the bike, but the
display shows no
reaction, and
values don’t
change.
RPM signal didn’t enter the display IC. Inspect RPM signal.
1. Inspect cable connections and the bridge board.
2. Inspect the reed switch and magnet.
3. Inspect the drive board CLK LED.
4. Inspect the reed switch and its wire.
1. magnet
2. reed switch
No
resistance I pedal the bike and press
resistance keys.
Resistance values
on the display
change. But there
is no resistance.
1. Inspect cable connections.
2. Inspect alternator startup. If alternator will not start unit,
there will be no resistance.
3. Inspect the electro-magnet and its wires.
4. Test whether the drive board emits voltage to the
electro-magnet.
1. drive board
2-1-1

Telemetry heart
rate detection
malfunction
Telemetry heart
rate malfunction 1. Inspect heart rate transmitter and its batteries. Replace batteries if batteries haven’t been replaced for a long time.
2. Inspect heart rate receiver board cable connections.
3. Test or replace the heart rate receiver board.
4. Inspect environment for sources of interference, such as
speakers and lights.
2. telemetry
heart rate
transmitter
3. telemetry
heart rate
receiver
board
Contact heart
rate
malfunction
Contact heart
rate malfunction 1. Inspect bridge board HTR cable. 2. Inspect HTR indicator LED on the drive board.
3. Replace the HTR board.
1. HTR board
C531U
Key
malfunction
(display)
No key function,
or continual key
function
1. Replace the display key switches. 1. display
keys
Remote
malfunction Press remote keys; display
shows no
reaction.
1. Inspect the remote and bridge board wire connections.
2. Replace the remote controller. 1. remote control C531U
Excessive
resistance Pedal on the unit; resistance
is too heavy.
1. Inspect all wire connections and whether screws have
created an electrical short.
2. Move the flywheel with your hand to see whether the
electro-magnet is stuck on the flywheel.
3. Inspect whether drive board components have an
electrical short, sending maximum power to the
electro-magnet, causing excessive resistance.
1. drive board
Total distance 1. Press workout level<▲>+<▼>+<stop> to see total
distance.
2-1-2

Troubleshooting
Model: C520U/C531U
Malfunction: Unit will not start (alternator).
Circumstance: Pedal on the unit; the display does not light.
Possible causes: 1. Wires are not connected.
2. Drive board is malfunctioning.
Troubleshooting: 1. Inspect wire and bridge board connections.
2. Inspect the alternator wires.
3. Inspect wire connections and fuse F1 and power
indicator LED on the drive board.
4. Replace the drive board.
5. Inspect the display board IC pins.
3-1-1
Drive
Board
Display
board
Alternator
Reed switch
Drive board
F1 fuse
Inspect power and CLK
LED indicators.
Inspect alternator
wire connections.
Inspect IC
Display power indicator LED1
Inspect reed switch

Troubleshooting
Model: C520U/C531U
Malfunction: Unit will not start (battery).
Circumstance: Display shuts off when no one pedals.
Possible causes: 1. Wires are not connected.
2. Battery voltage is too low.
Troubleshooting: 1. Inspect all wire and bridge board connections.
2. Inspect battery voltage. Normal: 5.5V or more.
3. Inspect the drive board F2 fuse.
4. If battery voltage is lower than 5.5V, pedal at over 50 RPM to
recharge the battery.
3-2-1
Drive
Board
Display
board
Battery
F3 fuse
Power LED
Test battery voltage.
Display requires 5.3V or
more to operate.
Inspect IC
Display power supply LED1.

Troubleshooting
Model: C520U/C531U
Malfunction: No RPM value
Circumstance: 1. No RPM value appears.
2. When you pedal the display shows no response.
Possible causes: 1. Reed switch and magnet
2. Wires are not connected.
Troubleshooting: 1. Inspect reed switch and magnet.
2. Inspect all cable connections.
3. Inspect the drive board CLK indicator.
4. Pedal at one rotation per second. Display RPM value: 60.
3-3-1
Display
board
Drive board
Speed sensor
Reed switch and magnet
Inspect drive board CLK indicator
LED lights when reed switch and
magnet make contact.

Troubleshooting
Model: C520U/C531U
Malfunction: No resistance
Circumstance: Pedal the unit. There is no resistance.
Possible causes: 1. Wires are not connected.
2. Drive board is defective.
Troubleshooting: 1. Inspect all cable connections.
2. Inspect whether RPM value appears when one pedals.
If not, inspect the reed switch wires.
3. Inspect whether alternator can start unit.
4. Inspect drive board fuse. Inspect whether the drive board emits voltage to
the electro-magnet.
5. Inspect the electro-magnet wires and
whether the electro-magnet attracts metal.
3-4-1
Drive board
Display board
Alternator
Reed switch
Electro-
magnet F1 fuse
Inspect drive board
CON2 voltage
LEV 5 6.3V
LEV 1510V

Troubleshooting
Model: C520U/C531U
Malfunction: Resistance is excessive.
Circumstance: Pedal the bike; resistance is excessively heavy.
Possible causes: 1. There is an electrical short in the cables.
2. Drive board components have an electrical short.
Troubleshooting: 1. Inspect all cable connections. Inspect cables for damage.
2. Inspect drive board power components for a short.
3. Replace the drive board.
3-5-1
Drive
board
Display board
Electro-
magnet
Inspect IGBTs for a short

Troubleshooting
Model: C520U/C531U
Malfunction: Telemetry heart rate malfunction
Circumstance: Heart rate value does not appear.
Possible causes: 1. Telemetry transmitter batteries.
2. Heart rate receiver board malfunction.
3. Environmental interference, possibly from
lights or speakers.
Troubleshooting: 1. Replace the heart rate transmit-
ter strap or its batteries.
2. Inspect heart rate receiver board connections.
3. Inspect the HTR board LEDs.
3-6-1
Display
board
HR receiver
board
Telemetry heart rate receiver board

Troubleshooting
Model: C531U
Malfunction: HTR heart rate malfunction
Circumstance: Hold HTR contacts with both hands;
Heart rate values are incorrect.
Possible causes: 1. HTR wires are not connected.
2. HTR board is defective.
3. Display wires are not connected.
Troubleshooting: 1. Inspect display wire connections.
2. Inspect bridge board HTR wires.
3. Inspect HTR contact wires.
4. Inspect HTR board indicators.
5. Replace the HTR board.
3-7-1
Display
board
HTR board
SENSOR-L
SENSOR-R
HTR board indicator LEDs
LED Name Explanation
LED1 Telemetry Flashes to indicate incoming telemetry signal.
LED2 HTR contact
Lights to indicate hands on contact plates.
LED3 HTR output Flashes to indicate incoming HTR (contact)
signal.
LED4 Heart rate
signal output
Flashes to indicate heart rate signal output to
the display