Service manual
Table Of Contents
- Revision Table
- Introduction
- Chapter 1
- Features and General Specifications
- Chapter 2
- Mechanism Configuration and Operating Principles
- Printer Mechanism Operating Principles
- Print mechanism unit
- Print head unit movement
- Wire movement when a single dot is printed
- Printing a character (9x9 font)
- Paper Feed Mechanism Unit
- Paper loading (semi-automatic loading)
- Paper feeding
- Ribbon Feed Mechanism Unit
- Ribbon feeding
- Detection Mechanism Unit
- Home position detection mechanism
- Paper detection mechanism
- Paper roll near-end detection mechanism (optional)
- Auto-cutter mechanism
- Ribbon Switch Mechanism Unit
- Electrical Circuitry Operating Principles
- Principles of Operation
- Printer Mechanism Driver Circuits
- Printer Mechanism Operating Principles
- Chapter 3
- Handling and Maintenance
- Chapter 4
- Troubleshooting
- Chapter 5
- Disassembly, Assembly, and Adjustment
- Small Part Specifications
- Disassembly
- Sub-assembly A
- Main Assembly 1
- Main Assembly 2
- Main Assembly 3
- Main Assembly 4
- Main Assembly 5
- Main Assembly 6
- Main Assembly 7
- Main Assembly 8
- Main Assembly 9
- Main Assembly 10
- Main Assembly 11
- Main Assembly 12
- Main Assembly 13
- Main assembly 14
- Main Assembly 15
- Main Assembly 16
- Main Assembly 17
- Main Assembly 1 (Case Unit)
- Main Assembly 2 (Case Unit)
- Main Assembly 3 (Case Unit)
- Main Assembly 4 (Case Unit)
- Main Assembly 5 (Case Unit)
- Main Assembly 6 (Case Unit)
- Main Assembly 7 (Case Unit)
- Main Assembly 8 (Case Unit)
- Main Assembly 9 (Case Unit)
- Main Assembly 10 (Case Unit)
- Main Assembly 11 (Case Unit)
- Main Assembly 12 (Case Unit)
- Adjustment
- Appendix
- Appendix
- Addendum 1
- Main Circuit Board Types and Maintenance
- Addendum 2
- Lower Plate Change and ROM Spacer Abolition
- Addendum 3
- Auto-Cutter Release Tab Change
2-26 Mechanism Configuration and Operating Principles Rev. B
Confidential
Printer Mechanism Driver Circuits
Print head driver circuit
The head driver signal is output from CPU (U5) pins 64 to 72. Receiving this drive signal,
transistor array QM1 and QM2 and transistor array QM3 turn On, Off, and drive the head.
Power supply time to the head is adjusted by the supplied power voltage. The CPU (U5)
changes the power voltage between analog and digital at AN0 (pin 7) and decides and controls
the head power supply time according to the internal time table.
To prevent damage to the head during excessive printing, a heat sensor has been installed in the
print head. An analog-digital conversion of the partial pressure difference between the heat
sensor and R18 is carried out in AN1 (pin 8) of the CPU (U5) and the temperature is calculated. If
the head is overheating or working improperly, the ERROR LED flashes.
Figure 2-26 Print head driver circuit
COM (# 3.5.7 )
# 5
# 7
# 1
# 3
Print head unit
HEAD1
HEAD5
HEAD6
HEAD2
RM3
87
65
43
21
Q4
9
7
5
3
8
6
4
2
1
1
0
QM1
Q6
Q5
Q7
+5V
RM4
87
65
43
21
Q8
9
7
5
3
8
6
4
2
1
1
0
QM2
Q10
Q9
Q11
HEAD3
HEAD7
HEAD9
HEAD8
+24A
D7
68
69
65
72
Q12
R20
1
2
3
CN7
4
5
6
7
8
9
10
11
12
13
14
15
P44
P45
P41
P50
HEAD4
67
66
70
P43
P42
P46
71
P47
64
P40
8 HD TEMP
P61/AN1
7 V DTC
P60/ANO
6
AVSS
5
AVCC
C30C31
R45
R46
R18
C19
C29
R8
+
C33
_
R19
+24DT
# 9
C0M ( # 1.2.9 )
THEM1
THEM2
# 4
# 6
# 8
COM (# 4.6.8 )
# 2
FG
D27 D28
Q13
U5
+5V
+5V
D50
D32
D38
D39
D40
D41
D42
D43
D45
D44