Rev.B
Overview of Electric Circuits Appendix F-3
TM-L90 Service Manual
Confidential
The table below lists the main elements of the main circuit board unit and their functions.
Table F-1 Main elements and their functions for main circuit board unit
Block
Location
Signals on
diagram
Description
Functions
CPU and
peripherals
U4
—
—
CPU and custom logic I/O ports
U7
—
max 8M bit (512K*16 bit)
Program memory
U8
—
4M bit (256K*16 bit)
DRAM
U9
—
8M bit (512K*16 bit)
Font Memory
X1
—
40 MHz
System clock (for U4)
X2
—
25 MHz
System clock (for U4)
Power
supply
system
F1
154004T
4A, surge-proof
Printer power supply fuse
Q1
+24V
24 VDC, 1.7A
Semiconductor switch for power supply to
mechanism
QS1, QS2
+24V OUT
24 VDC, 1.7A
Semiconductor switch for power supply to
printer
U1K
DKP
24 VDC, 1A
Power supply to drawer
LH9
VH 2
Power supply for thermal head
UZ1
VIO
5 VDC, 1.5A
Power supply to I/O logic circuits
UZ2
VBUS
3.3 VDC, 0.15A
Power supply to bus logic circuits
Connectors
CN6
I/F BOARD
—
Universal interface board (UIB) connector
CN10
HEAD
—
Connector for thermal head unit
connection (front of the printer)
CN11
NE
—
Connector for paper near-end
connection
CN12
RE
—
(for TM-T90 only)
CN13
Label photo
—
Connector for transmission sensor photo
connection
CN4
SUB
—
Connector for sub circuit board
connection
CN7
SWITCH
—
Connector for switch circuit board
connection
CN8
A/C
—
Connector for autocutter unit connection
(front of the printer)
CN9
PF
—
Connector for PF motor connection
Switch
SW1
—
—
Power switch (front of the printer)
Interfaces
QK2, QK3
DKD 1,
DKD 2
24 VDC, 1A
Drawer drive transistor output signal
Mechanism
drivers
QMA1
ACM+,
ACM-
24 VDC, 0.25A
Driver and output signal for push-pull cutter
motor
UP1, UP2
PF_A+,
PF_A-,
PF_B+,
PF_B-
24 VDC, 0.7A
Driver and output signal for PWM power
supply control of bipolar stepping motor
for feed mechanism