Many users confuse their printer's toner cartridge with its drum unit. On printers from Brother, Xerox, and enterprise Canon models, these are physically separate units.

Symptoms of an Empty Toner Cartridge:

• Progressive fading across the page.
• A clear vertical void where toner powder ran out first.

Symptoms of a Failing Drum Unit:

• Recurring grey dots, blotches, or background haze across crisp text.
• Ghosting (faint secondary echoes of previous lines) even with a brand new toner cartridge installed.