1-28 Service Manual
5016-001
Detecting New Cleaning Unit
Detecting the cleaning unit in the Fuser Assembly
A thermal fuse is attached on the contact point A in the cleaner unit.
When the cleaner unit is placed inside the fuser unit, contact A
contacts contact B. The circuit is then complete through the thermal
fuse. When primary power is applied to the printer, a current flows
through the thermal fuse detecting a new cleaner unit and the print
counter resets to ‘Zero.’
As the temperature of the hot roll and cleaning roll rise, the
temperature around the thermal fuse also rises, eventually causing
the thermal fuse to blow.
Note: The fuse will generally blow after primary power has been
applied following the printing of two or three sheets of paper. At this
time the temperatures of the blown fuse and surrounding parts are
70 degrees C and about 100 degrees respectively.
When predetermined sheets of paper are printed, a warning
displays. When additional sheets are printed, the printer stops until
the unit is replaced. When a new unit is placed, repeat the previous
step.