Dell E1709W, Руководство по обслуживанию

Страница: 6 / 62

Service Manual
5
Chapter 3- CIRCUIT THEORY
Block Diagram
There are 2pcs PCBA in this monitor, one is power& inverter board which is a single layer board,
and one is interface board&keypad which is OSD control. The system function block diagram as
below
This PWA is included switching power supplier, inverter for CCFL and interface board.(fig.1)
Power
Transformer
MOSFET
Photocoupler
+5V DC output
Snubber
&Schottky
Feedback
Control
Feedback
and OVP
PWM Control IC
LD7575
+12V DC output
2
1
ON/OFF Control
INL837
T
o
P
a
n
e
l
C
C
F
L
La
m
p
2
Snubber
&Schottky
Power
MOSFET
Rectifier&
Filter
Circuit
AC Input
90V~264V
Brightness Control
+5V DC
T
o
IF
B
o
a
rd
+5
V
DC
AC Line Filter
La
m
p
1
In
ver
te
r
Tr
a
n
sf
or
m
e
r
Fig.1