Brother TD-4000, Service Manual

Page: 16 / 139

II - 9
2.3 MAIN PCB
Figure 2.3-1 and Figure 2.3-2 show the block diagram of the main PCB. The main
PCB consists of the following components.
(1) CPU (Including ROM and RAM)
(2) Flash ROM, SDRAM
(3) EEPROM (4Kbits)
(4) Power supply ON/OFF circuit, FEED button ON/OFF circuit, CUT button ON/OFF
circuit, and LED ON/OFF circuit
(5) Head power supply ON/OFF circuit
(6) Full cutter motor driver circuit, and Media feed motor driver circuit
(7) Media position detect sensor circuit, and Cover open sensor circuit
(8) Head temperature detect circuit
(9) Cutter home position sensor circuit
(10) Reset circuit
(11) USB interface circuit
(12) RS232C interface circuit
(13) Ethernet interface circuit
Figure 2.3-1 Block Diagram of Main PCB (For 100/120V model)
CPU
<For 100/120V model>
850E/MA3
ROM: 256KB
RAM: 16KB
FEED, CUT button
Green LED, Red LED
Oscillator circuit
7.6MHZ
DC motor
for full cut
For tape feed
driving
EEPROM
(4Kbits)
FROM 64Mbits
(Max. 64Mbits)
TD-4100N:
SDRAM 128Mbits
(Max. 128Mbits) TD-4000:
SDRAM 64Mbits
(Max. 64Mbits)
RS232C
IC
RS232C
IF
Step motor
Bipolar constant current
drive circuit
100/120V
Switch
INT
(NEC)
+25V
output
LAN IF LAN IC LAN 9115
USB IF USB IC D12
Cutter home position
sensor
Cover open sensor
POWER button
Cover left sensor
Fan motor unit
AC power supply
Switching
power supply
Power supply
shunt PCB
+2.5V power
supply circuit
+3.3V power
supply circuit
Photo sensor for
detecting top edge
of media
DC motor
Normal/reverse
drive circuit
Thermal head
temperature detect circuit
Thermal head
+25V power supply
voltage detect circuit
16bits bus
+2.5V output
(for CPU power supply)
+25V output
(for drive power supply)
+3.3V output
(for logic power supply)
Lock
signal
Key PCB
+5V output
+8V output
TD-4100N only