Canon imageRUNNER ADVANCE C255 Series Service Manual page 340

Field Remedy
1. Select "-3" for the following service mode.
COPIER (LEVEL2) > ADJUST > HV-TR > 1TR_xxxx
The setting range is "-50" to "50". (Default: 0)
Changing the setting value by "1" changes the primary transfer current by 1 microampere.
Select "1TR_xxxx" according to the paper type and size in use, and the color for which the symptom occurs.
The following shows an example in the case of Plain 1 (64 to 75 g/m2)/A4.
If the problem occurs in yellow:
Change the setting value in the following service mode to "-3".
( Lv.2 ) COPIER > ADJUST > HV-TR > 1TR-TGM
( Lv.2 ) COPIER > ADJUST > HV-TR > 1TR_TGC
( Lv.2 ) COPIER > ADJUST > HV-TR > 1TR_TGK4
If the problem occurs in magenta:
Change the setting value in the following service mode to "-3".
( Lv.2 ) COPIER > ADJUST > HV-TR > 1TR_TGC
( Lv.2 ) COPIER > ADJUST > HV-TR > 1TR_TGK4
If the problem occurs in cyan:
Change the setting value in the following service mode to "-3".
( Lv.2 ) COPIER > ADJUST > HV-TR > 1TR_TGK4
Paper type and size
Plain 1 (64 to 75 g/m2)
Plain 2 (76 to 90 g/m2)
Recycled 1 (64 to 75 g/m2)
Recycled 2 (76 to 90 g/m2)
Plain 3 (91 to 105 g/m2)
Recycled 3 (91 to 105 g/m2)
Other paper types
2. Select the following service mode, and press the [OK] button to execute the primary transfer ATVC control.
COPIER > FUNCTION > MISC-P > 1ATVC-EX
3. Output the image where the symptom occurred, and check that the symptom does not occur.
■ Fogging Around the High Density Image in a Low Humidity Environment
Location
Secondary transfer voltage
Cause
When paper that has been left in a low humidity environment is fed, fogging [1] may occur around the high density image.
[A] indicates the paper feed direction.
When a high density image is transferred to a high surface resistance paper, a larger secondary transfer voltage is required.
When the surface resistance of the paper is high, toner on the paper cannot be retained and scatters on the non-image area due
to the insufficient secondary transfer voltage in the high density area, and thus this symptom occurs.
Smaller than A4 1TR_TGM3, 1TR_TGC3,
(210 mm) 1TR_TK43
A4 (210 mm) or 1TR_TGM, 1TR_TGC,
larger 1TR_TGK4
ALL 1TR_TGM3, 1TR_TGC3,
1TR_TK43
ALL 1TR_TGM2, 1TR_TGC2,
1TR_TK42
329
Color for which the symptom occurs
Yellow Magenta
1TR_TGC3, 1TR_
TK43
1TR_TGC, 1TR_
TGK4
1TR_TGC3, 1TR_
TK43
1TR_TGC2, 1TR_
TK42
6. Troubleshooting
Cyan
1TR_TK43
1TR_TGK4
1TR_TK43
1TR_TK42