Rev. B
Mechanism Configuration and Operating Principles
TM-U200D/U200PD Technical Manual
+5V DC control circuit
The +5V regulator circuit switches the +24V power input and converts it to +5V. The switching
regulator IC (U1) switches the +24V input, smooths it via C1, and o5V. Power for the
RS-232 is generated by the internal charge-up circuit on the RS-232 interface driver.
Control Circuitry
Reset circuit
The reset circuit is used to prevent the CPU from operating erratically and the print head from
printing unexpectedly during the period of unstable voltage immediately after the power is
turned on. To accomplish this, the OUT terminal output (pin5) of the reset IC (U9) is supplied to
the CPU (U5) as the -RESET input signal (pin 21).
The reset IC (U9) monitors the +5V voltage. When the voltage is 4.5V or more, the reset is
released for the CPU and other components, and the printer becomes ready.
In addition, the C terminal (pin 4) of the reset IC (U9) is connected to the reset signal (DSR signal
or pin 25 input signal) from the host interface via DIP switches 2-3 and 2-4. If a reset signal is
applied to this pin, the reset IC output goes low and the CPU and other components are reset.
The reset signals differ depending on the interface specifications:
Figure 2-18 Power supply circuit diagram
Q1
D47
Q2
D48
Q3
D49
R5
R6
R7
+5V
U2
G
N
D
VIN
5
3
4
1
SEN
SW
2
VOUT
D4
U3
G
N
D
VIN
5
3
4
1
SEN
SW
2
VOUT
D3
U4
G
N
D
VIN
5
3
4
1
SEN
SW
2
VOUT
D5
+
C14
_
+
C45
_
+
C16
_
+
C7
_
+
C9
_
C6
C8
C12
L1
C11
R17
+
C10
_
F1
U1
G
IN
10
1
6
5
LIN
OUT
+
C2
_
C3
C1
+
C5
_
R42
R9
{
5 V
+
C41
_
F . G
CN1
1
2
3
4
1
2
3
SH
30 WDTOUT
73 +24COM SW
74 CRCOM SW
P80 WDTOUT
P51/T04
P52/T05
U5
76 PFCOM SW
P53/INT1/TI4
+30V
GND
N . C
F . G
G
N
D
+24DT
HEAD COM
A / C COM
DKD COM
GND
CR COM
GND
GND
PF COM
GND
2
1
SW1
+5I
+24DT
D6
GND
GND
FG
C13
1M
P.G
Power switch
+24A
+24B
+24C
GND
1
1
Q27
Q24
R59
Summary of Contents for TM U200D - B/W Dot-matrix Printer
Page 2: ...technical manual TM U200D U200PD EPSON English 4005680 ...
Page 4: ...EPSON SEIKO EPSON CORPORATION Printed in Japan E9608130 0000SE ...
Page 145: ...Rev B Disassembly Assembly and Adjustment 5 49 TM U200D U200PD Technical Manual ...
Page 146: ...5 50 Disassembly Assembly and Adjustment Rev B ...
Page 147: ...Rev B Disassembly Assembly and Adjustment 5 51 TM U200D U200PD Technical Manual ...
Page 148: ...5 52 Disassembly Assembly and Adjustment Rev B ...
Page 154: ...Appendix A 6 Rev B Main Circuit Board A Parts Layout ...
Page 155: ...Rev B Appendix A 7 TM U200D U200PD Technical Manual Main Circuit Board C Parts Layout ...
Page 156: ...Appendix A 8 Rev B RS 232 Serial Interface Circuit Board Parts Layout ...
Page 169: ...Rev B A 21 TM U200D U200PD Technical Manual Case Unit Lubrication Points Diagram ...