SC201

What it means

Polygon mirror motor did not reach or hold lock speed. No write, so no image.

Some Aficio models log this as SC320 / SC335.

Likely causes

• Polygon motor worn (bearing) — most common on high-click IM C
• Laser unit connector unseated after PCU work
• 24 V / polygon driver

1. 1ListenFrom the right side / rear, listen for polygon spin at warm-up and at the start of a job. No spin → laser optics unit (LOSU).
2. 2ReseatPower off. Reseat the laser unit harness. Confirm the unit is fully locked in the frame — a unit sitting up 2 mm will throw 201/202/220.
3. 3Replace LOSUReplace the laser optics unit. Do not open the polygon chamber. After install, print a test chart and check color registration (skew).

Parts to have on the truck

• Laser optics unit (polygon)
• Laser harness

Related procedures

• Free run (SP5-801)

  Run the engine without paper to hear a motor, see a belt, or reproduce a 500/440.

Related codes