Eeprom; Reset Circuit; 1.3.10 Engine I/O; 1.3.11 Panel I/O - Brother MFC8440D Service Manual

7/13/2019
1.3.8

EEPROM

The EEPROM is BR24126 type of two-wire method with a 8192 x 8bit configuration.
1.3.9

Reset circuit

The reset IC is a R3112N281C. The reset voltage is 2.8V (typ.) and the LOW period of reset is
22.4ms (typ.)

1.3.10 Engine I/O

The interface with the engine PCB is by full-duplex synchronous serial method, of which
transfer rate is 520kbps.
ENGDI
3D

1.3.11 Panel I/O

The interface with the panel PCB is by full-duplex synchronous serial method.
http://slidepdf.com/reader/full/brother-8840d-service-manual
U15
Aurora
Fig. 3-10
U5
C75
5
CD
C103
4
TP310 NC
3
0V GND
R3112N281C
Fig. 3-11
U7
TP200
253
ENGRSTN
TP201
254 255
ENGDI ENGDO
ENGDI
1D
Aurora
Fig. 3-12
Fig. 3-13
Brother 8840D Service Manual
MFC-8440/8840D/8840DN, DCP-8040/8045D/8045DN
VDD3
C71
C103
2
VCC
C77
TP4
R84
1
VOUT 0V
68
C101
9
3
1
R
VDD3
TP202
R142
1k
TP203
R138
100
TP205
TP204 R141
100
VDD5
3 1 1 3 2
0 0 0 0 0
1 1 1 1 1
C C
C C C
4 3
2 3 2
4 5 4
5 5
1 1 1
1 1
C C C
C C
0V
3-7
SERVICE MANUAL
VDD3
ENGINE
CN9
k
7
.
4
L10
0 1
3.3V
L14
0 5
RESET
L12
0 3
TXD
L13
0 4
RXD
L15
0 6
5V
k
7
0
.
4
4
1
R
L11 0
2
0V
B6B-PH-K-S
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