Toshiba e-STUDIO520 Service Handbook page 484

l NO
l
YES
Is the value for the image quality sensor output value (Light source off) 05-292 outside the
range between 50 and 230?
Is the value for the image quality sensor light amount adjustment result 05-296 "0 "or "255"?
Is the value for the image quality sensor light amount adjustment result 05-296 other than "0
"or "255"?
Is the power voltage output (Vout2) that is created in the sensor outside the range?
l YES
l
l
l
l
l
l
l
l
NO
Replace the LGC board, and perform the image quality control enforcement / condition
check (image check; described later).
<<Procedure of the "enforced performing of image quality control"/"control status check">>
Set the value for the number of times of sensor abnormality (08-800) to "0".
Set the value for the Image quality closed-loop control (08-1809), (08-1810) to "0" (valid).
Perform the "enforced performing of image quality control" (05-290).
Check the control status of the image quality control (05-291) and number of times of sen-
sor abnormality (08-800).
Are both values for 05-291 and 08-800 "0"?
Perform the test print (04-113: Secondary scanning direction 33 gradation steps). Is the
image printed properly?
YES
NO
See " Troubleshooting for the Image" and clear the problem.
• Is the value for 05-291 "1"?
Attempt the procedure again from the beginning.
• Is the value for 05-291 "2"?
Pattern abnormality. Go back to "(1) Pattern abnormality " and clear the problem.
• Is the value for 05-291 "4"?
Sensor abnormality. Go back to "(2) Sensor abnormality" and clear the problem.
* When the value for 05-242 (Drum surface potential sensor control status) is other than
"0", there is a problem on the drum surface potential control. Clear the problem with the
troubleshooting for surface potential control related.
e-STUDIO520/523/600/603/720/723/850/853
TROUBLESHOOTING
Check the power system, replace the switching power supply, and then
perform the image quality control enforcement / condition check (image
check; described later).
1) Is toner adhered to the connector that connects the cleaner unit and
this equipment and the connector almost short-circuited or discon-
nected? Replace the harness if needed, and then perform the image
quality control enforcement / condition check (image check;
described later).
2) Replace the LGC board, and perform the image quality control
enforcement / condition check (image check; described later).
3) Replace the image quality sensor, and perform the image quality
control enforcement / condition check (image check; described later).
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