104 Itu Error - Lexmark C752 Service Manual

5060-2XX

104 ITU Error

The ITU has an optical sensor that watches for a piece of reflective tape on the inside of the image belt. This
tape is read every revolution of the belt. If a signal is not received from the belt sensor within a certain time
period, the printer posts an error due to the loss of signal. There are several causes for the loss of signal. First,
the belt has tracked too far to the front or rear of the printer. In this case, the belt is still turning, but the reflective
tape is no longer passing within view of the belt sensor. This is considered a belt tracking error and is posted as
a 104 ITU Error. The other causes of a signal loss could be a belt stall, meaning the belt is not turning, or a true
signal loss, which would be due to a bad sensor, broken cable, loose connection, or bad system board. These
other causes post as a 100 ITU Error.
To assist the printer in determining what is the cause of a signal loss, there is a buffer that records the belt
position for the last 50 revolutions. If the printer loses the belt signal, it refers to the buffer. If the buffer shows
significant mistracking before signal loss, it will post a 104 ITU Error. If the buffer shows that the belt has been
tracking in the center before signal loss, it posts a 100 ITU Error. Due to memory restrictions, the buffer is not
saved during POR. This means, if a printer posts a 104 ITU Error, so the belt is tracked off, and the customer or
servicer turns off the printer to clear the error, when the printer starts up, it will still not see the belt signal and will
now post a 100 ITU Error because the buffer is empty. When servicing a printer for a 100 ITU Error, it is
important to view the error log. See
at this point. Do not try to print the log. Look for past occurrences of 100 ITU Errors preceded by a 104 ITU Error.
Step Action and questions
1 Make sure all packing material is removed from the
printer. The Detensioner is located underneath the
toner cartridges. Make sure the ITU Detensioner is
removed. Remove the Detensioner by pulling up on the
red handle on the right side of the ITU.
Note: All the print cartridges must be removed to gain
access to the Detensioner packing material.
Has all packing material been removed from the
printer?
2
Check the ITU Release Lever for correct operation.
The ITU Release Lever is the blue lever located on the
left upper side frame above the ITU opening and can
be seen by opening and lowering the MPF Assembly.
When locked the lever should be at the 6 o'clock
position. When unlocked it should be in a 3 o'clock
position. Undue pressure is not required to operate the
lever.
Does the ITU release lever operate correctly?
3 Check the second transfer roll installation.
Is it installed correctly?
2-44
Service Manual
"Viewing the error log" on page 3-31. The error log can only be displayed
Yes No
Go to step 2 Remove any
remaining
packing material
from the printer
Go to step 3 Repair as
necessary
Go to step 4 Reinstall the
second transfer
roll.