Muratec MFX-C4000 Field Engineering Manual page 190

Problem Description
Foggy Backgrounds
for a Particular Color
Foggy Background
for All Colors
Periodic White/
Black/Color Spots
White Spot on Solid
Image
Service Manual
Alignment & Troubleshooting
Cause Description
1. Low Charging Bias
1. Mis-Sensing Outter
Temperature
2. Wrong Charging
Bias from HVPS
1. Damage/
Contamination on
OPC
2. Damage/
Contamination
Charging Roller
1. Unstable T2 Transfer
Roller Nip
2. High T2 Transfer
Voltage
Action to Resolve
[1. Low Charging Bias]
1.1) Check the external temparature sensor and humidity
sensor.
1.2) If the sensor is normal, check the Charge Bias[TM #105-
0010~0016]. If or not, change the value.
1.3) Check the Charge Bias [EDC #105-0000~003]. If it is
defective, replace the HVPS.
1.4) If it is normal, check the contact between charge high
voltage harness and developing unit.
1.5) If it is normal, check the OPC grounding.
[1. Mis-Sensing Outter Temperature]
1.1) Check the external temparature sensor and humidity
sensor.
[2. Wrong Charging Bias from HVPS]
2.1) If the sensor is normal, check the Charge Bias[TM #105-
0010~0016]. If or not, change the value.
2.2) Check the Charge Bias [EDC #105-0000~003]. If it is
defective, replace the HVPS.
2.3) If it is normal, check the contact between charge high
voltage harness and developing unit.
2.4) If it is normal, check the OPC grounding.
[1. Damage/Contamination on OPC]
1.1) In case of falling off the coating on OPC, the periodic black/
color spot will be occured.
1.2) If charging is defective by OPC damage, white spot will be
occured.
[2. Damage/Contamination Charging Roller]
2.1) If the charging roller has the damage or contamination, the
periodic black/color spot will be occured.
[1. Unstable T2 Transfer Roller Nip]
1.1) Check the T2 Engage/Disenage motor running[#EDC #100-
0010]. If it is defective, replace the T2 Engage/Disenage
Motor.
1.2) Check the T2 Engage/Disenage sensor [#EDC #100-0011].
If it is defective, replace the sensor.
1.3) Check the T2 roller during T2 Engage/Disenage motor
running [#EDC #100-0010]. If it is defective, replace the T2
Unit.
1.4) Check the ITB Drive Roller Ground. If it is defective, replace
the ITB.
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