Error c7990 Printer no

empty drum unit its full of waste toner each side of drum unit has plastic covers that pop off empty out the unit thoroughly and vacuum inside

This error indicates that the waste toner area of the drum unit is full. One way to resolve is to replace the drum unit, power the printer on, and the error will be cleared. Another, more economical way, is to manually remove drum unit, remove square end caps located on both ends, and vacuum out or carefully dump into a trash bag. Just be careful...dumping toner is messy.

Clean the waist bottle

Suggestions at the link below:

Thread Kyocera FS 1035 error C7990

This service code means that the waste toner reservoir inside the drum unit is full and that the printer has printed over 100.000 pages.

waste toner full
try emptying the waste toner from the drum unit if possible.
replace drum unit.

its a waste toner error put a new one in if the error persist check all the sensors you may also have to replace the drum

please get the closes kyocera company to do it ,it will cost less the u doing it.

What to do if the current display is "Machine Failure Call Service C7990" but few days ago it displays "Toner Waste Box is Full".?

El error corresponde a "deposito de desecho lleno"; Sacas la unidad completa donde va el toner, colocas la pestilla verde donde la flecha indica cleaner, en cada lado lateral trae un tornillo en un agujero profundo, quitarlos y luego quitar las tapas pequeñas, vacias el contenido en la basura y listo.. (favor no hacerlo con ropa blanca porque queda negra)