Caution For Correction; Toner Density Correcting Method - Toshiba e-STUDIO650 Service Handbook

Defective area
Decreasing toner density
Image quality sensor/
Surface potential sensor
Main charger
Note 1:
If the output from the main charger or the developer bias is abnormal, replace the high-voltage transformer with a new one and output
the chart again. If the output stays abnormal, check if the harness connecting the LGC board and high-voltage transformer is open-
circuited, if the power supply is normal and if the main charger wire is dirty.
Note 2:

Toner density correcting method

Change the setting value 'Toner density life correction setting (08-414)' (6 is the default setting.)
3: Appox. 1.5% lower than the current value
4: Appox. 0.8% lower than the current value
5: Appox. 0.3% lower than the current value
6: The current value (Default setting)
<Caution for correction>
When increasing or decreasing the toner density too much, the image may become poor or the life of developer material, cleaner,
photoconductive drum and fuser unit, etc. may shorten. Therefore it is not recommended to correct (to shift) the toner density
basically. If it is shifted, make sure that the image may be improper in a few minutes after shifting.
e-STUDIO550/650/810 TROUBLESHOOTING
Step Check Items
12 Is the performance of the auto-toner
sensor control normal?
13 Is the toner density low?
14 Are the image quality sensor and the
surface potential sensor normal?
15 Is the main charger dirty?
7: Appox. 0.3% higher than the current value
0: Appox. 0.5% higher than the current value
1: Appox. 0.8% higher than the current value
2: Appox. 1.5% higher than the current value
Prescription
Check the performance of the auto-toner
sensor.
Correct the toner density.
(Note 2: See 'Toner density
correcting method'.)
Check the performance of the image
quality sensor and the surface potential
sensor. (See the trouble shooting related
with the image quality control.)
Clean or replace it.
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Remarks
JUNE 2002 © TOSHIBA TEC