Printer Section: Low Image Density - Konica Minolta Bizhub 162 Service Manual

17. Image quality problem
17.2.14

Printer Section: Low image density

A. Typical Faulty Images
B. Troubleshooting Procedure
Step
The image changes when "Toner Replenisher" is exe-
1 cuted.
• "Toner Replenisher" of Utility
The image changes when "ID Adjust" and "VG Adjust" are
2
executed.
3 Image transfer current contact is dirty, folded, or bent.
4 Developing bias contact is dirty, folded, or bent.
5 High Voltage Unit (HV1) connectors is loose.
ATDC Sensor (UN1) is dirty with foreign matter (such as
6
paper dust) other than developer.
The following voltages develop from the ATDC Sensor
(UN1).
<Check Procedure>
7 Check voltage across a Master Board pin and GND when
the Power Switch is turned ON.
• DC5.39 V to 8.15 V across PJ10A-1 and GND
• DC1.41 V to 4.98 V across PJ10A-3 and GND
The following voltage is supplied from the Master Board
(PWB-A).
<Check procedure>
8
• Check that there is 24 V developing across the Master
Board pin and GND when the Power Switch is turned
ON (during a copy cycle or a standby state).
168
Check
Field Service Ver. 1.0 Apr. 2005
4011T003AA
Result
• Replenish the supply of
YES toner using Toner
Replenisher.
• Readjust. For details,
YES see ADJUSTING/SET-
TING.
• Clean, correct, or
YES
change.
• Clean, correct, or
YES
change.
YES • Reconnect.
YES • Clean.
• Change ATDC Sensor
NO (UN1) and then change
developer.
• Change IU.
YES • Change High Voltage
Unit (HV1).
• Change Master Board
NO
(copier: PWB-A).
Action