Horizon Fitness T303 Treadmill Service Manual

Chapter 1: Serial Number Location

1.1 Serial Number Location

The serial number for the Horizon Fitness T303 Treadmill is located on a label on the treadmill frame. The label displays the model number (TM444-2KM), the model name (T303), and the serial number (S/N: TM4441103BD00399). It also indicates the product is "DESIGNED IN U.S. MADE IN CHINA".

[Image Description: A treadmill is shown from a three-quarter front view. A close-up label is shown near the front base, indicating model and serial number details.]

Chapter 2: Engineering Mode

2.1 Engineering Mode

To enter Engineering Mode:

1. Press and hold the INCLINE UP and SPEED DOWN keys simultaneously for 3-5 seconds until the Engineering Menu appears on the display.
2. Use the INCLINE or SPEED UP and DOWN keys to scroll through a list of parameters.
3. Press ENTER to enter a parameter setting.
4. Use the INCLINE or SPEED UP and DOWN keys to change the parameter.
5. Press the START key to save the change to the parameter.
6. Press and hold the STOP key to exit Engineering Mode and return to normal operation.

[Image Description: A close-up view of the treadmill's console, showing buttons, a display screen, and handlebars.]

2.2 Engineering Mode – Overview

*Demo Mode – The console will display Figure A after the removal of the safety key; Demo On – 60 seconds after the removal of the safety key, the console will enter into DEMO ON MODE. The LED and LCD will display in turns (Figure B).

[Image Description: Figure A shows a treadmill console display with "SAFETY-KEY-O" and workout mode indicators. Figure B shows a treadmill console display with workout metrics like Time, Distance, Speed, Watts, Calories, and Heart Fit.]

Chapter 3: Electrical Diagram

3.1 Electrical Diagram

The electrical diagram, labeled T303-1 CONSOLE WIRE CONNECTION SCHEMATIC, illustrates the wiring connections for the treadmill console. It shows the main console unit with various ports and connections, including interfaces for the motor, incline system, speed sensor, and user interface buttons. It details how these components are interconnected via cables and connectors, providing a visual guide for electrical troubleshooting and repair.

[Image Description: A schematic diagram showing the layout and connections of various electronic components within the treadmill, including the console, motor controller, and sensors.]

Chapter 4: Troubleshooting

4.1 Troubleshooting – No Power to the Console

Symptom: The power switch is in the on position, but the console will not turn on.

Reason:

1. The outlet is not providing the correct power, or the power cord / switch is defective.
2. The power receptacle or power wiring to the MCB is defective.
3. The MCB is defective.
4. The console cable or console is defective.

Solution:

1. Check to see if the power switch is lit. If it is not, try a different outlet. If the power switch still does not light up with a known good outlet, replace the power switch.
2. Check to see if the MCB has power. There is a red power LED on the MCB that should be lit.
3. If the MCB does not have power, check the connection of the power wiring from the power receptacle to the MCB. Use a multi-meter to measure voltage at AC1 & AC2; AC voltage should be the same as local standard voltage (110V-240V). If the AC voltage value is standard, replace the MCB as it is defective.
4. If the MCB does have power, check the connection of the console cable wire at the MCB and UCB. Remove the console cable from the MCB, and use a multi-meter to measure the DC voltage between the "GND pin” (Pins 4 & 5) and the “+ 15V Pin” (Pins 7 & 8). DC output is normally around 15VDC. If there is no output, replace the MCB.
5. If output is around 15VDC, check the console cable for pinches or kinks. If any damage is found, replace the console cable. Disconnect the console cable at the UCB and measure the DC voltage between the "GND pin” (Pins 4 & 5) and the “+ 15V Pin” (Pins 7 & 8). DC output is normally around 15VDC. If there is no output, replace the console cable.
6. If the console cable connections and voltage are all good, replace the UCB.

[Image Description: Left image shows a red illuminated power switch. Right image shows a close-up of a circuit board with a red LED lit on an MCB. A third image shows a circuit board with connections labeled AC1 and AC2.]

4.2 Troubleshooting – Keypads Not Responding

Symptom: The keypads are not responding when pressed.

Reason:

1. The keypads are defective.
2. The console is defective.

Solution:

1. Press the SPEED DOWN and INCLINE UP keys together for 3 seconds to enter Engineering Mode. Use the SPEED UP or DOWN keys to scroll to ENG0, and press ENTER. Test each of the keypads using Display Test. The console should chime as each key is pressed.
2. If any keypads are not chiming during Step 1, check the connection of the keypad ribbon cable at the UCB. Even if the connection appears good, detach the ribbon cable from the UCB, and then re-attach and retest. Replace the keypads as needed.
3. If the keypads do not resolve the issue, replace the console.

4.3 Troubleshooting – No Console Response

Symptom: The power is on and the console lights up, but the treadmill does not run when keys are pressed.

Reason:

1. The keypads are defective.
2. The console is defective.
3. The drive motor is defective.
4. The speed sensor is defective.
5. The MCB is defective.

Solution:

1. Check if the console beeps when all keys are pressed. If not, troubleshoot the keypads as outlined in Section 4.2.
2. Enter Engineering Mode (See Section 2.1), and scroll to ENG 1 (Hardware Test). Press the ENTER key and then the START key. The belt should start moving. Press the SPEED UP and DOWN keys; if the speed changes, the console is ok. If the speed does not change, replace the UCB.
3. Turn off the power switch, and open the upper motor cover. Remove the red & black wires coming from the motor to the MCB, and use a multi-meter to measure the resistance of the drive motor wire. If the resistance is higher than 10 Ω, the drive motor is defective. Replace the drive motor. If the resistance is lower than 10 Ω, the drive motor is ok.
4. Check the connection of the speed sensor (encoder disk group) at the MCB. Remove the speed sensor from the motor and clean it, then re-test. If the speed sensor is clean and has a good connection but still will not operate, replace the speed sensor.
5. Replace the MCB as the last step if the unit still does not run after taking the above actions.

[Image Description: Figure A shows a circuit board with a speed sensor connector. Figure B shows a motor with an attached encoder disk (speed sensor).]

4.4 Troubleshooting – Incline Motor Issues

Symptom: The incline motor does not move up or down when prompted.

Reason:

1. The keypads are defective.
2. The incline motor is defective.
3. The MCB is defective.

Solution:

1. Check if the console beeps when the incline keys are pressed. If not, troubleshoot the keypads as outlined in Section 4.2.
2. Enter Engineering Mode (See Section 2.1), and scroll to ENG 1 (Hardware Test). Press the ENTER key. Press the INCLINE UP and DOWN keys. If beeps can be heard from the 2 relays at the MCB, the MCB is ok. Check the connection of the incline motor at the MCB; if this is good, replace the incline motor.
3. If the relays do not beep when the INCLINE UP or DOWN keys are pressed, or if the incline motor does not resolve the issue, replace the MCB.

[Image Description: An image of the treadmill console displaying "ENG 1" and workout mode information. Two images of circuit boards are also shown, one highlighting a relay and the other showing a hand connecting wires to a component.]

4.5 Troubleshooting – Noise Issues

Symptom:

1. Thumping noise twice per rotation on a new machine.
2. Rubbing / grinding noise.
3. High pitched “bell-like” sound from under the motor cover.
4. Banging or clunking sound.
5. Slapping / thunking / squeaking sound with each footstep.
6. Rubbing sound underneath the treadmill.
7. Squeaking noise when raising / lowering the deck into storage positions.
8. Squeaking / grinding noise when using elevation.

Reason:

1. Roller or belt noise.
2. Moving component is rubbing.
3. Optic disk rubbing.
4. The unit is not level.
5. Running deck or belt system is not tight.
6. The running belt is rubbing on something.
7. The air shock needs lubrication.
8. The incline motor is missing washers or needs lubrication.

Solution:

1. Roller or belt noise: If this is a new unit, some noise is normal as the running belt forms around the rollers. Check that the belt is centered and tensioned correctly. Remove and clean the rollers if needed. Replace the rollers or running belt as needed.
2. Moving component rubbing: Remove the motor cover and check the drive belt for alignment and make sure it is not slipping or is frayed / cut in any way. Replace the drive belt if needed. Make sure the optic disk on the motor is not rubbing the speed sensor. Turn the motor by hand to see if motor brushes or bearings are rubbing. Replace the motor if needed. Check the front and rear rollers, replace if needed.
3. Optic disk noise: Check that the optic disk is tight on the motor and not rubbing the speed sensor.
4. Unit not level: Check that all levelers are touching the ground. Move the treadmill to another flat surface.
5. Running deck / belt noise: Check that the running deck is tightly attached to the frame. Check the deck shocks for deterioration or crumbling. Replace if needed. Check to see if the air shock is making this noise, lubricate or replace if needed.
6. Belt rubbing on something: Make sure the belt is not rubbing on the deck, side rails, or deck shocks. Check that the running belt is tensioned correctly.
7. Air shock noise: Lubricate or replace the air shock as needed.
8. Incline motor noise: Check that the incline motor connection points include Teflon washers. Lubricate the incline motor worm screw and connection points with grease. Replace the incline motor.

4.6 Troubleshooting – Speaker / Audio Issues

Symptom:

1. No sound through the speakers but headphones work.
2. No sound through headphones but the speakers work.
3. No sound through speakers or headphones.
4. IPod not charging.
5. Speakers buzzing.
6. Sound from one speaker only.
7. Shock from headphones.

Reason:

1. One of the speaker boards has a bad connection or is faulty.
2. Bad connection between the earphones and console.
3. Bad connection between one of the audio boards and the console.
4. The iPod or iPod dock has a bad connection.
5. The speakers are not getting a clear signal through the speaker wires.
6. The speaker or speaker wire are defective.
7. There is a grounding issue with the earphones or console.

Solution:

1. Speaker board issue: Check the connection of the wires going from the speakers to the speaker power board. Check the connection of the wires going from the speaker power board to the amp board. Check the connection of the wires going from the amp board to the console. Replace the speaker or amp boards and wiring. Replace the speakers. If the speaker board, amp board, wiring, and speakers do not solve the issue, replace the console.
2. Headphone connection issue: Verify the connection of the music player to the dock or audio adaptor cable. Verify the audio adaptor cable connection at the console. Replace the headphone jack. Replace the audio adaptor cable.
3. Audio board connection issue: Verify the connection of the music player to the dock or audio adaptor cable. Verify the audio adaptor cable connection at the console. Replace the audio adaptor cable. Replace the console.
4. iPod/iPod dock connection issue: Verify the connection of the iPod. Verify the connection of the iPod dock at the console. Replace the iPod dock.
5. Speaker signal issue: Check the speaker wire connections. Check for any kinks or cuts in the speaker wires. Replace the speaker wiring. Replace the speakers.
6. Speaker/wiring issue: Check the speaker wire connections. Switch the speaker connections from one speaker to the other to see if sound switches sides. If the sound does not switch sides, replace the speaker board. If the sound does switch sides, replace the speaker and speaker wires.
7. Grounding issue: Try a different set of headphones. Check the grounding of the console.