Service manual

30 July, 2001 PHOTOCONDUCTOR UNIT
6-31
Detailed
Descriptions
6.4.7 PCU DETECTION (DEVELOPMENT UNIT DETECTION)
The drum positioning plate [A] contains eight push switches [B]. These detect when
a new PCU or a new development unit has just been installed. They also detect if
the PCUs and development units are in the machine.
Each PCU and each development unit includes a pin [C], which activates the
switch when the drum positioning plate is closed. On a new unit, this pin does not
activate the switch. When the unit is driven for the first time, the pin comes out and
activates the switch.
After the machine is turned on or the front cover is closed, the machine checks
each switch (result 1 in the table). Then the machine drives the PCUs and
development units for 5 seconds and checks each switch again (result 2 in the
table). The condition detected by the machine depends on the combination of
results, as shown below.
Result 1 Result 2 Detection Action
OFF OFF
The PCU or development unit is
not placed in the machine, or the
drum positioning plate is not
secured by the two screws.
The machine displays an
error message.
OFF ON
A new PCU or development unit
has just been installed.
The machine resets the
counter for the PCU or
development unit.
ON ON
The current PCU or
development unit is present.
The machine goes to standby
mode.
NOTE: If some PCUs or development units are not installed, the machine displays
error messages in the following order.
(M dev→M PCU→C dev→C PCU→Y dev→Y PCU→K dev→K PCU)
G060D307.WMF
[A]
[B]
[C]