Oki B721 Maintenance Manual

Oki Data CONFIDENTIAL
45487001TH Rev.1
6-62 /
6. Troubleshooting procedure
6.5.2.(15) Toner cartridge cannot be recognized. (Errors 543)
(15-1) Error caused by the consumable items.
Check item Check work
Actions to be taken
at NG
(15-1-1) Consumable items installation condition
ID unit and toner
cartridge
Check that the ID unit is installed in the
normal position. Check that the lock lever of
the toner cartridge is locked.
Correct the
installation to
the normal
installation
condition.
(15-2) Error caused by the toner sensor
Check item Check work
Actions to be taken
at NG
(15-2-1) Toner sensor condition
Toner sensor Is the receptor of the toner sensor stained? Wipe off the
stain from the
toner sensor.
Toner sensor Confirm that the toner sensor works normally
by using the SWITCH SCAN function of the
self-diagnostic mode.
Place a white paper in front of the toner
sensor, and check if the SCAN state changes
or not.
Replace the
toner sensor
board or the
FFC between
the toner
sensor board
and the PU/CU
board.
Note! Toner sensor operation check method using the SWITCH SCAN function of
the self-diagnostic mode.
(1) How to check operation of the toner sensor at the printer side.
1. Status change of the toner sensor can be checked from the control panel using
the self-diagnostic mode. First, switch the display to the control panel display.
For the method of switching the display to the control panel display, refer to
section 6.3.2.3 Switch Scan Test
2. Remove the ID unit and the toner cartridge (TC) from a printer. There is a
window inside a printer opposing the ID side when viewed from the front of a
printer. The toner sensor is located inside the window.
3. Place a white paper 3 mm away from the sensor window. The white paper
should be placed in the manner of opposing the toner sensor.
4. When light is reflected by a white paper so that incident light falls on the toner
sensor, the control panel display shows "L". When the paper is moved so that
any light is not reflected by the paper so that the incident light does not reach
the toner sensor, "H" is displayed on the control panel.
5. If the control panel display toggles between "H" <-> "L" as a paper is flipped
in front of the toner sensor, it indicates that the toner sensor and the related
system of the printer are working normally.
Action to be taken at NG
• Clean surface of the toner sensor to remove the stains due to residual toner
and paper dust.
• Check the connection condition of the FFC cable between the PU/CU board
and the toner sensor board (97T).
• Perform the operation checkagain.If the situation has not bee improvedand
remains unchanged, replace the PU/CU board or the toner sensor board (97T).
(2) How to check operation of the toner sensor at the toner cartridge (TC) side
1. To the position where the toner sensor is confirmed to be operating normally
in the printer itself by the above paragraph (1), install the TC and the ID unit to
check operations by observing display on the control panel.
Action to be taken at NG
• Check operation condition of the respective ID motors by using the Motor &
Clutch Test of the self-diagnostic mode.
• CleansurfaceofthesilverreectorplateonthesideofIDtoremovestains.(Stain
due to toner or paper dust)

Oki B721 Specifications

General

Print Technology	LED
Resolution	1200 x 1200 dpi
Processor	533 MHz
Memory	256 MB
Connectivity	USB, Ethernet
Duplex Printing	Standard