SC120

What it means

Carriage never found the HP sensor on power-up or at the start of a scan.

Subcodes

• 120-01HP not detected on init
• 120-02HP did not go off after leaving home

Likely causes

• HP sensor dirty, unplugged, or failed
• Scanner motor / belt / cable snapped
• Carriage jammed on a foreign object or unseated rail
• Scanner motor driver on BICU/IOB

1. 1Watch HPPower on with the glass cover open. Carriage should seek HP and stop. No motion → motor/driver. Overshoot → HP sensor.
2. 2Inspect the pathLook for a dropped staple, paper clip, or unseated timing belt. Re-seat the carriage on both rails.
3. 3HP sensorClean the HP sensor window. Check the actuator flag on the carriage. Replace the sensor if it never changes state (SP5-803 input check).
4. 4Motor and beltReplace scanner motor or timing belt if the carriage binds or the belt is glazed/slipping.

Parts to have on the truck

• Scanner HP sensor
• Scanner motor
• Timing belt
• Carriage

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