Oki MC860 MFP, Руководство по обслуживанию

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43967002TH Rev.1
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Oki Data CONFIDENTIAL
2. Theory of Operation
Light-shielding plate
Toner sensor
Shutter
Remedial measure against the respective errors
• CALIBRATION ERR, DENS SENSOR ERR
Check 1. When the above error indication is displayed, check the connection
status of the sensor cable.
If the connection status shows any abnormality, correct it to the normal
status.
Check 2. Check if the sensor surface becomes dirty or not by the toner or paper
powder.
If it is found dirty, clean it completely.
If any problem was not found even when the checks 1, 2 and 3 were
executed, problem might have occurred in circuitry. Replace the density
sensor, relay PCB (P6Y.PCB), PU PCB(PU.PCB)and the connection
cables one after another with the good one to locate the cause of the
error. Check that the error does not occur when each PCB is replaced.
• DENS SHUTTER ERR
Check 3. Check if the open/close status of the sensor shutter is normal or not by
using the MOTOR&CLUTCH. TEST of the self-diagnostic function. If
open/close is not executed completely, replace the shutter unit.
• DENS ID ERR
Check 4. Remove the ID unit and check if any excessive toner exists or not on
the drum surface.
Replacement of the LED head (out of focus) or replacement of ID unit
When a new ID unit is going to be used for the trial purpose, use the
Fuse keep mode of the maintenance menu.
Detection principle of toner sensor
Detection of the toner low is executed by the toner sensor (reflection sensor) that is installed
inside the unit. The light-shielding plate is installed inside the ID and rotates in synchronism
with agitation of toner. At the same time, ID contains the shutter. The shutter operates in
synchronism with the operation lever of the toner cartridge and can detect whether the toner
cartridge is normally installed by using the toner sensor. If the light-shielding plate or the
toner sensor becomes dirty by the toner, of the ID unit faces against the toner sensor in the
specified location due to the defective installation of the ID unit, the detection may not be
executed normally so that the toner sensor error may be issued.
Operating principle of toner counter
The image data is expended into the binary data that can be printed by a printer. Then
number of the binary data is counted by LSI as the number of printing dots. Amount of the
used toner is calculated from this count value, and remaining toner display is shown on the
menu. However, detection of toner LOW (remaining amount display on LCD) is detected by
sensor when physical amount of toner remaining inside the ID is decreased lower than a
specified amount.
Operating principle of ID counter and fuser counter
ID counter: Amount of drum rotation when 3 sheets of the A4 size paper are printed
consecutively, is counted as 1 count after the actual number of drum
rotations is divided by 3.
Belt counter: Amount of belt rotation when 3 sheets of the A4 size paper are printed
consecutively is counted as 1 count after the actual number of belt rotations
is divided by 3.
Fuser counter: When length of a print paper is shorter than the paper length of Legal size
13 inch, the fuser counter is incremented by 1 count. If the paper length
exceeds the paper length of Legal size 13 inch, the number of counts is
determined after calculating the number of times of the Legal 13 inch paper
length. (Numbers after decimal point are rounded up.)