Toshiba DP120F Service Manual page 416

The presence or absence of recording paper placed in the bypass tray is detected by the
bypass tray paper empty sensor connected to CN14 on the Mother PBA. The recording paper,
if present, pushes down the actuator of the bypass tray paper empty sensor for turning on. This
causes the SCPE signal to be HIGH and input to the PTC GA (IC45) to detect the presence of
recording paper placed in the bypass tray.
The size of recording paper placed in the bypass tray is detected by the bypass tray paper size
sensor connected to CN28 on the Mother PBA. The recording paper size select plate pushes
down the contact of the bypass tray paper size sensor for turning on. At this time, the number
of contacts to be pushed down varies depending on the set position of the paper size select
plate, This causes the SCPS0-2 signals to be HIGH or LOW to detect the recording paper size
input to the PTC GA.
The detection conditions of the respective signal levels and recording paper sizes are listed in
the table below.
Recording paper size
The recording paper placed in the bypass tray is fed by driving the bypass tray paper pickup
solenoid connected to CN13 on the Mother PBA. The PTC GA causes the SCPF signal to go
HIGH to turn on Q252. This causes the SCPF signal to be at GND level to drive the bypass tray
paper pickup solenoid for feeding the recording paper.
Signal Name Type
SCPE I
SCPS0-2 I
SCPF O
March 2000 © TOSHIBA TEC
SCPS0
LG LOW
LT LOW
A4 LOW
Other HIGH
Active
H Bypass Paper Empty Detect Signal
L Bypass Paper Size Detect 0-2 Signals
H Bypass Tray Paper Pickup Solenoid Drive
Signal
SCPS1
LOW
LOW
HIGH
HIGH
Description
7-107
SCPS2
LOW
HIGH
HIGH
HIGH
Destination
PTC GA
PTC GA
Q252
DP120F/DP125F Circuit Description