What should I do when the 'Toner Low' warning appears on the SCX-4200?

When the Toner Low message displays, the Status LED blinks red, and white streaks or light printing may occur. You can temporarily restore print quality by removing the toner cartridge and rolling it 5 or 6 times to redistribute the remaining toner, then reinserting it. Note that white streaks or light printing may still occur even after redistribution, and the cartridge will eventually need to be replaced. (Page 8.3)