How to clear toner alert
open the front door and close again, wait for toner to load.
if this problem persist,open the front door and remove toner unit,use a flat screw driver to press on the door sensor and check if the toner motor is working properly.
if the motor is in good condtion,service the toner unit and make sure that the unit is toner free and insert new toner.
if this condition persist, enter the sp mode and clear all memory by sp 5801 for mp5ooo, aficio 1035-4545,645,2035,2045,235,735 or sp801 for 1022,1027,1505 and restart the machine.
for aficio 1035-4545,645,2035,2045,235,73 enter sp21093 and 21094 mode before making a copyor else the error sc329 will appear.
good luck