Toshiba e-STUDIO556 Service Manual page 779

8.3.21 Troubleshooting for image quality control
[Corrective action when "Service Recommended for IQC" is blinked]
Check the control status of the image quality control (05-2133).
<When "2" is displayed: pattern error>
The pattern is not read or formed correctly.
<When "4" is displayed: sensor error>
The sensor output is out of the acceptable range.
(1) Corrective action for pattern error
Output the test print (04-114: 33-gradation pattern in secondary scanning direction).
Check the value for 05-2136 and 05-2137. Either of the values is 630 or more.
NO 
l
l
l
l
l
l
l
l
l
l
l
l
l
l

YES
Is the printout blank?
YES 
l
l
l
l
l
l
l
l

NO
Is the image density of the image uneven or remarkably low?
NO 
l
l
l
l
l

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<Stains on the test print>
If the cleaning blade is not installed to the cleaner unit properly, install it
correctly.
If the cleaning blade is damaged, etc., replace it, and then perform the
image quality control enforcement / condition check (image check;
described later).
<The image density of the test print is remarkably high>
Replace the LGC board or PLG board, and then perform the image
quality control enforcement / condition check (image check; described
later).
<The test print is normal>
Replace the image quality sensor, and then perform the image quality
control enforcement / condition check (image check; described later).
Check the output of 05-2020 (developer bias) and 05-2040 (main
charger grid bias). The output reference value of the developer bias is -
500±22V and that of the main charger grid bias is -394±22V. If the
output is outside of the range, replace the high-voltage transformer. If it
is within the allowance range, replace the PLG board or LGC board
(See "Troubleshooting for the Image"). When the equipment is ready for
printing, perform image quality control enforcement / condition check
(image check; described later).
1. Perform the test print (04-114) again. If the printout is blank, return to
the previous step "Is the printout blank?".
2. If the test print is normal, check the surface of the image quality
sensor, clean it or replace it, and then perform the image quality
control enforcement / condition check (image check; described later).
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e-STUDIO556/656/756/856/557/657/757/857
ERROR CODE AND TROUBLESHOOTING
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