1.3.14 Power Supply - Brother DCP 8040 - B/W Laser - All-in-One Service Manual

1.3.14 Power supply

+5V is generated by the 3-pin regulator from astable 7V supplied from the LVPS. +5V is used
for the IEEE1284 interface, the LD PCB and the engine PCB. In addition, +1.9V is generated
by the 3-pin regulator from 3.3V supplied from the LVPS. +1.9V is used for the CPU within the
ASIC and the logic circuit.
C138
6.3V 6V
C220
C157
C22
16V
C137
Q5
C104
VCC
2
GND OUT
1
3
NJU7223DL1-19
VDD7
D2
RB751V-40
Q6 NJM2391DL1-19
OUT
VCC
C158
GND
C104
FG1
MFC-8440/8840D/8840DN, DCP-8040/8045D/8045DN
VDD3
D1
RB751V-40
VDD1.8
C128
C125
16V
C10
C104
VDD7
0V
VDD3
VDD5
C140
C151
C10
C104
16V
0V
Fig. 3-16
3-9
SERVICE MANUAL
LVPS
CN8
2
+7V
3
0V
0V
C220
C141
6.3V 6V
1
+3V
B3B-EH