Brother HL-4000CN Service Manual page 305

A B
2.3.1 Machine self test
MCU AND HVPS PWB
1 PL15.1
CONTROL
LOGIC
2
3
2.1.1
+3.3VDC J311 1
BRN
2.1.1
DC COM
2
VIO
2.1.1
+5VDC
3
GRY
4
2.1.1
DC COM
4
VIO
5
6
C D
ESS PWB
PL16.1
S1
EEPROM EEPROM
1
(U8) (U9)
P/J 14 P/J 1
CONTROL
LOGIC
P/J 10
P/J 12
P/J 14
P/J 33
+3.3DC
DC COM
P/J 34
+5VDC
P/J 45
DC COM
VI-8
E F
IOT ERROR
RAM slot PL16.1
RAM 128MB 50 DIMM
When replacing ESS
PWB,remove EEPROM(U8,U9)
from ESS PWB and install
them on new ESS PWB.
Pararell
USB
Font Card
HDD ASSY PL16.1
NIC EXP ASSY PL16.1
Ethenet 100Base TX / 10BaseT
ESS ERROR
2.3 Machine Run Control
G H J
2
2.3.3
1
2
2.3.3
2
Imaginary Line