Interpretation
What this message does — and does not — prove
Official meaningThe printer is not detecting the drum unit in the expected installed state.
Do not assumeBuying toner will not resolve a missing/drum-detection message if the drum assembly is absent or not seated.
Safe sequence
Work through the manufacturer-scoped path
- 01
Open the front cover.
- 02
Remove and inspect the combined toner/drum assembly without touching sensitive drum surfaces.
- 03
Confirm the toner cartridge is installed in the drum and reseat the assembly fully.
- 04
Close the cover and recheck the status.
Stop / escalate
When not to keep experimenting
If a correct genuine/compatible drum is seated and still not detected, use Brother support/service guidance.