Precautions; Developer Bias; Transfer; When Blotched Image Appear - Toshiba e-STUDIO206L Service Manual

6.8.2

Precautions

[ 1 ] Developer bias

Note for adjustment
Adjust the developer bias if fogging occurs over the entire image even though the main charger grid
voltage and toner density are appropriate. However, the following may occur if the developer bias is
lowered too much:
• Image contrast becomes low.
• Image is patchy or blurred.
• The carrier in the developer material adheres to the photoconductive drum, causing scratches
around the cleaner.

[ 2 ] Transfer

Items to check before adjustment
Blotched image or poor transfer can be also caused by matters other than defective adjustment of
transfer output. Check the following items before adjusting the transfer charger. If there is no problem,
adjust the output of the transfer.
• Are the transfer roller unit, transfer roller and power supply spring properly installed? Is there any
foreign matter or damage on the transfer roller surface? Is the transfer guide deformed?
• Is the process unit properly installed? Is the developer magnetic brush in contact with the drum?
Is the process unit worked correctly? Is the toner density low?
• Is the copy paper fed straight? Is the copy paper abnormally moist?
• Is the rotation of the registration roller normal?
• Is the separation output different from the set value?
• Is the developer bias value an appropriate one?
Note for adjustment

When blotched image appear:

• If blotched image appear in halftone areas, lower the transfer output value. Remember that transfer
performance becomes low if the transfer output value is lowered too much.
When poor transfer occurs:
Increase the transfer output value under the following conditions. Remember that blotched image
appear if the transfer output value is increased too much.
• Poor transfer occurs although the transfer roller unit, transfer roller and power supply spring are
properly installed and no abnormality exists on the appearance of the transfer roller.
• Thick paper has been frequently used.
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SETTING / ADJUSTMENT
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