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error Brother
Error Code Toner - Yellow LED (blinking)
Toner cartridge has reached end of life.
? What Causes This
Toner cartridge is empty or has reached end of usable life.
✓ How to Fix It
Replace the toner cartridge immediately. See User's Guide Chapter 5 for replacement instructions.
Source: page 5 of the official manual
From the manual
This error code appears in:
Brother HL-2000 Monochrome Laser Printer