MX-1800N (serv.man16). Section 8 - Self Diagnostics Trouble Codes - Sharp Copying Equipment Service Manual (repair manual). Page 17

MX-1800N  SELF DIAG AND TROUBLE CODE  8 – 17

 

 

 

 

 

 

Trouble content

The transfer belt surface is scanned by the image 
density sensor before starting the registration, and 
adjust the sensor gain so that the output is kept at 
a certain level. However, the output is not within 
the specified range though the senor gain is 
adjusted.

Section

PCU

Case 1

Cause

Image density sensor trouble, harness connection 
trouble between PCU PWB and the image density 
sensor, image density sensor dirt, transfer belt 
cleaning trouble, calibration plate solenoid 
operation trouble

Check and 
remedy

Check the sensor and the harness. Check the 
calibration plate solenoid operation and the 
transfer belt surface state.
If the trouble is not cleared, replace the image 
sensor exclusively used for registration, replace 
the transfer belt, replace the calibration plate, 
replace the solenoid, or replace the PCU PWB 
according to the check result.

Trouble content

The low-density rising point or the high-density 
saturation point cannot be calculated because of a 
calculation error in the primary approximation 
formula of the sensor output ratio for the LSU 
PWM value obtained from the first step patch print 
result when executing the half tone process control 
in BLACK.

Section

PCU

Case 1

Cause

Image density sensor trouble, harness connection 
trouble between PCU sub PWB and the image 
density sensor, image density sensor dirt, transfer 
belt cleaning trouble

Check and 
remedy

Use SIM44-2 to execute the process control gain 
adjustment. If "ERROR" is displayed, check the 
sensor and the  harness. If the adjustment is 
completed, check the drum surface state and the 
belt surface state.

Trouble content

The low-density rising point or the high-density 
saturation point cannot be calculated because of a 
calculation error in the primary approximation 
formula of the sensor output ratio for the LSU 
PWM value obtained from the first step patch print 
result when executing the half tone process control 
in CYAN.

Section

PCU

Case 1

Cause

Image density sensor trouble, harness connection 
trouble between PCU sub PWB and the image 
density sensor, image density sensor dirt, transfer 
belt cleaning trouble

Check and 
remedy

Use SIM44-2 to execute the process control gain 
adjustment. If "ERROR" is displayed, check the 
sensor and the  harness. If the adjustment is 
completed, check the drum surface state and the 
belt surface state.

Trouble content

The low-density rising point or the high-density 
saturation point cannot be calculated because of a 
calculation error in the primary approximation 
formula of the sensor output ratio for the LSU 
PWM value obtained from the first step patch print 
result when executing the half tone process control 
in MAGENTA.

Section

PCU

Case 1

Cause

Image density sensor trouble, harness connection 
trouble between PCU sub PWB and the image 
density sensor, image density sensor dirt, transfer 
belt cleaning trouble

Check and 
remedy

Use SIM44-2 to execute the process control gain 
adjustment. If "ERROR" is displayed, check the 
sensor and the  harness. If the adjustment is 
completed, check the drum surface state and the 
belt surface state.

Trouble content

The low-density rising point or the high-density 
saturation point cannot be calculated because of a 
calculation error in the primary approximation 
formula of the sensor output ratio for the LSU 
PWM value obtained from the first step patch print 
result when executing the half tone process control 
in YELLOW.

Section

PCU

Case 1

Cause

Image density sensor trouble, harness connection 
trouble between PCU sub PWB and the image 
density sensor, image density sensor dirt, transfer 
belt cleaning trouble

Check and 
remedy

Use SIM44-2 to execute the process control gain 
adjustment. If "ERROR" is displayed, check the 
sensor and the  harness. If the adjustment is 
completed, check the drum surface state and the 
belt surface state.

Trouble content

The low-density section output is greater than the 
middle-density section output when connecting the 
low-density section approximation formula and the 
middle-density section approximation formula 
(formula of the sensor output ratio for the LSU 
PWM value) from the second step patch print 
result when executing the half tone process control 
in BLACK.

Section

PCU

Case 1

Cause

Image density sensor trouble, harness connection 
trouble between PCU sub PWB and the image 
density sensor, image density sensor dirt, transfer 
belt cleaning trouble, transfer belt cleaning trouble

Check and 
remedy

Use SIM44-2 to execute the process control gain 
adjustment. If "ERROR" is displayed, check the 
sensor and the  harness. If the adjustment is 
completed, check the drum surface state and the 
belt surface state.