Oki B 4100 Maintenance Manual page 530

Note: The toner supply roller and the developing roller are supplied with bias voltages
40055101TH Rev.4
required during the developing process as shown below. -450 VDC is supplied to
the toner supply roller, -300 VDC to the developing roller.
Base
EP drum
Connected and bias voltage
supplied when the cover is
closed.
Toner supply roller
Developing roller
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