Solution to reset waste ink tank (error 5B00): Power off printer Hold Resume button then press and hold POWER, the beeper will sound once. Hold POWER and release RESUME Press RESUME twice, then release all buttons When the indicator lights steady, press RESUME three or four times. The indicator should be orange. Press Power to set data Link : More about Canon MX850
Reset printers and cartridge. Printers problem solving,tips, tricks and tutorial.