Block Diagram; Chapter 3- Circuit Theory - Dell 2209WA Service Manual

Service Manual

Chapter 3- CIRCUIT THEORY

Block Diagram

Dell 2209WA consists of a main body and a stand (base). The main body
contains a Innolux LCD module with 6 CCFL lamps, There are 4pcs PCBA
in this monitor, one is power & interface & Audio board , one is invert board ,
one is keypad which is OSD control, and one is USB stretch board located
on the right side back cover.. The block diagram is shown as below.
(fig.1)
POWER
PFC+PWM
controller
IC SG6901
PFC
control
Bulk
PFC boost
E-CAP
circuit
Rectifier&
Filter
Circuit
Standby
controller
IC LD7575
AC Line Filter
AC Input
90V~264V
PWM
control
Feedback
Main Power
PWM circuit
Start up
circuit
PWM
control
Standby
Power PWM
circuit
5
Feedback
control
+24V DC output
to Inverter
Transfor and
Isolate
Rectifier and
(Main Power filter circuit
transformer)
Transfor and
Isolate
Rectifier and
(Standby Power filter circuit
transformer)
Feedback
control
24V ON/OFF
circuit
To Inverter
24V ON/OFF Contro
CCFL ON/OFF Cont
Brightness Control
AUDIO ON/OFF Con
12V DC
regulator and
+12V DC output
ON/OFF circuit
+5V DC output +5V DC output
GND
+24V /+12V/+5V DC Jack AUDIO Detect
OVP circuit
Power saving Power Saving contr
circuit
(OPTION)
Contol Signal
From/TO IF Board