← All guides
Medium · 6 minError codesBrother

Replace the belt unit (color laser)

On a color laser, the belt unit carries toner past each colour drum. When it reaches its limit, the printer halts with “Replace Belt Unit.”

01 · Identify — does this match what you see?

  • “Replace Belt Unit” on a color laser
  • Colour registration drifts before the warning
  • Printer refuses to print after the counter hits its limit

02 · Resolve — follow in order

  1. 1

    Open the front cover and remove all drum and toner assemblies.

  2. 2

    Pull the used belt unit straight out by its handle, keeping it level.

  3. 3

    Slide the new belt unit in until it seats; it only fits one way.

  4. 4

    Reseat each drum-and-toner assembly into its colour slot.

  5. 5

    Reset the belt counter via the panel (open front cover → hold OK/Clear → select Belt → Yes).

Pro tip

The belt counter can be reset without a new belt, but a worn belt causes persistent colour misregistration and stray toner marks. Replace it for real when warned.

03 · Applies to

HL-L8360CDWMFC-L8900CDWHL-L6480CW

Related fixes