MX-1800N (serv.man16). Section 8 - Self Diagnostics Trouble Codes - Sharp Copying Equipment Service Manual (repair manual). Page 18

MX-1800N  SELF DIAG AND TROUBLE CODE  8 – 18

 

 

 

 

 

 

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 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 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 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 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 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 patch density value is not in the range of the 
density correction reference density value (STD 
value) 

±30% at the upper limit or the lower limit 

bias voltage when executing the high density 
process control.

Section

PCU

Case 1

Cause

Image density sensor trouble, harness connection 
trouble between PCU PWB-image density sensor, 
dirt on image density sensor, transfer belt cleaning 
trouble

Check and 
remedy

1)

Use SIM44-2 to execute the process control 
sensor gain adjustment.

2)

If an error occurs, check the sensors and the 
harnesses.

3)

If the adjustment of 1) is completed, check 
the drum surface state, the belt surface state, 
etc.

Trouble content

The patch density value is not in the range of the 
density correction reference density value (STD 
value) 

±30% at the upper limit or the lower limit 

bias voltage when executing the high density 
process control.

Section

PCU

Case 1

Cause

Image density sensor trouble, harness connection 
trouble between PCU PWB-image density sensor, 
dirt on image density sensor, transfer belt cleaning 
trouble

Check and 
remedy

1)

Use SIM44-2 to execute the process control 
sensor gain adjustment.

2)

If an error occurs, check the sensors and the 
harnesses.

3)

If the adjustment of 1) is completed, check 
the drum surface state, the belt surface state, 
etc.

Trouble content

The patch density value is not in the range of the 
density correction reference density value (STD 
value) 

±30% at the upper limit or the lower limit 

bias voltage when executing the high density 
process control.

Section

PCU

Case 1

Cause

Image density sensor trouble, harness connection 
trouble between PCU PWB-image density sensor, 
dirt on image density sensor, transfer belt cleaning 
trouble

Check and 
remedy

1)

Use SIM44-2 to execute the process control 
sensor gain adjustment.

2)

If an error occurs, check the sensors and the 
harnesses.

3)

If the adjustment of 1) is completed, check 
the drum surface state, the belt surface state, 
etc.