Detection Whether New Or Used Imaging Cartridge; Right Door Interlock Switch - Epson EPL-N2700 Service Manual

EPSON EPL-N2700 / N2750
2.1.7 Detection whether New or Used Imaging
Cartridge
The printer has the function to detect whether the newly installed
imaging cartridge is a new one or used one. This function is equipped
because the PC drum counter has to be reset when the imaging
cartridge is replace with a new one. As shown in the figure below, a fuse
is connected in parallel with a resistor. In a new imaging cartridge, the
fuse is not blown. Accordingly, by measuring the voltage across the
resistor, the printer can determine whether the imaging cartridge is a
new one or not.
When the printer is turned ON after a new imaging cartridge has been
installed (or the right door has been closed after the imaging cartridge is
replaced), the fuse is blown. When the fuse has been blown, the PC
drum counter is cleared to enable detection of the image cartridge life.
A resistor is used for the counter and when power is turned OFF,
counter value, including other values, are stored in the EEPROM in the
imaging cartridge. When power is turned ON, the counter value is recall
from the EEPROM from the imaging cartridge for continuing counting.
Imaging cartridge
F4
R1
Internal
circuit
Figure 2-31. Internal Circuit of the Imaging Cartridge
NOTE: The counter is reset despite the fuse is not blown for some
reason.
Operating Principles

2.1.8 Right Door Interlock Switch

The right door is normally closed. It will be opened when the imaging
cartridge is replaced or jammed paper is removed.
n
n
4108s044
Printer Mechanism Operating Principles
When the door is open:
The door closed, the projection of the right door presses the
switch lever via the spring linked with the switch lever and the
switch is ON.
When it is opened:
The lever of the switch is set free so that the switch is OFF.
Right Door Interlock Switch (S2)
Projection
Right Door
Spring
Figure 2-32. Right Door Interlock Switch
Revision B
4108s045
84