Epson LQ 300 - Color Ribbon Sensorcircuit; Platen Gapsensorcircuit

LQ-300 Service Manual
Operating
PrinciMes
2.3.13 Color Ribbon Sensor Circuit
The printer’s color ribbon circuitry is shown in the figure below. The CPU receives signals (HIGH
or LOW) from the mechanical switch. The signal is HIGH (ON) when a color ribbon is installed
and is LOW (OFF) otherwise.
CPU (Cl)
P31
Printer
+5 v
tl
1
] Color Ribbon Sensor
51
I
I
Figure 2-25. Color Ribbon
2.3.14 Platen Gap
Sensor Circuit
; Color Upgrade Kit
I
Sensor Circuit Diagram
This printer has a connector switch to sense the PG(Platen Gap) adjust lever position. The CPU
receives a signal from the
PG sensor and recognizes the PG adjust lever position. The comector
switch is open(OFF) when the printer is in copy mode(PG adjust lever position:2-6) and is
close(ON) when the printer is in normal mode(PG adjust lever position:-l-+l). The printing speed
decrease in copy mode.
CPU (ICI)
P54
+5V
t
1
Figure 2-26. Platen Gap Sensor Circuit Diagram
Rev.A 2-19