What does error code C-2403 indicate on bizhub 421 Konica A-4403

See the 6th comment HERE

The error code means:
Problem with the toner bottle drive, most likely the toner rotation sensor
will need to be replaced or fixed.

Dirty toner bottle detect sensor. remove bottle and clean inside the housing, sensor is on the top left at the back of the housing.

Click Here or difinition and possiable fix for C-2403 error code.

Click start control panel administrive tools computer management then select event viewer depending on what operating sytem you have this may vary

extend the events there you will ((see errors in red)) you will no what exactly what the error was and at what time it occured
hope this helps