OKIDATA OL400e Series, Service Manual

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Service Manual for OL400e/OL410e/OL410e-PS
Chapter 2 Principles of Operation
2.5.02 Toner Low Sensor
The toner well of the image drum cartridge contains a toner agitator. Whenever the image
drum rotates, the toner agitator attempts to turn. A spring clip in the bottom of the toner well
(along with the proper amount of toner) holds the agitator at the bottom of the well. However,
when toner is distributed unevenly or an insufficient amount of toner is in the well, the toner
agitator will rotate. Therefore, as long as the toner well contains an adequate supply of evenly
distributed toner, the toner agitator will not rotate.
The toner sensor plate has a magnet embedded in it. Whenever the toner agitator is positioned
at the bottom of the toner well, the toner sensor plate is magnetically attracted to the toner
agitator. This causes the toner sensor plate to be lifted from the path of the toner sensor.
During a low toner condition, the toner agitator will rotate continuously. This causes the toner
sensor to turn ON / OFF as the image drum rotates. The operator panel will then display the
TONER LOW message.
During an unevenly distributed toner condition, the toner agitator will rotate until the toner is
distributed sufficiently. This causes the toner sensor to turn ON / OFF for only a few image
drum rotations. The operator panel will not display an error message since this is normal printer
operation.
If the toner sensor remains activated (ON), the operator panel will display the TONER SNS
message.
Customers may experience a "TONER SNS" or "TONER LOW" message with a brand new printer.
This may occur even though a new toner cartridge and drum have been installed.
This can occur for the first 30 pages. Between 30 and 200 pages, the CPU will turn OFF the
toner sensor. This will eliminate the message on the LCD. After 200 pages, the printer will
begin checking for proper operation of the toner sensor flag.
Customers should use the printers for at least 30 pages. The "TONER SNS" or "TONER LOW"
messages do not cause any print quality problems. The unit is in NO danger of suffering any
damage. If the problem persists for more than thirty pages, customers are directed to contact
a service center for warranty repair.
This information is documented in TSB 5604( ).
Copyright 1997, Okidata, Division of OKI America, Inc. All rights reserved. See the OKIDATA Business
Partner Exchange (BPX) for any updates to this material. (http://bpx.okidata.com)