One of the confirmed causes of the sensing errors is toner or dust on the imaging unit and machine contacts. The contacts can be easily cleaned by removing the imaging unit and brushing the toner off the contacts on the left and right side of the imaging unit. The mating contacts in the machine should also be brushed off. There are three contacts on one side of the unit and two on the other side. Please refer to the attached pictures of the Oki C5150 contact area that are typical of the C3000 and C5000 series machines.

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