LG M1921a Service Manual

LIPS Board Block Diagram
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EMI
COMPONENTS
LINE
100 ~ 240V
INPUT RECTIFIER
AND FILTERENERGY
TRANSFEROUTPUT RECTIFIER
AND FILTER
15V
5V
GND
SIGNAL
COLLENT-
IONPHOTO-
 COUPLER
ISOLATI ON
HVD C10 0KHz
PRIMARY SECONDA RY
50 ~ 60 Hz
PWM
COMTROL
CIRCUIT
Operation description_LIPS
1. EMI components. 
This part contains of EMI components to comply with global marketing EMI standards like FCC, VCCI, CISPR, the
circuit included a line-filter, across line capacitor and of course the primary protection fuse.
2....

EDID ADJUSTMENT
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Windows EDID V1.0 User Manual
Operating System: MS Windows 98, 2000, XP
Port Setup: Windows 98 => Don’t need setup
Windows 2000, XP => Need to Port Setup.
This program is available to LCD Monitor only.
1. Port Setup
a) Copy “UserPort.sys” file to   
“c:\WINNT\system32\drivers” folder
b) Run Userport.exe
c) Remove all default number
d) Add 300-3FF
e) Click Start button.
f) Click Exit button.2. EDID Read & Write
1) Run WinEDID.exe  
2) Edit Week of Manufacture, Year of Manufacture,...

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220
IBM
Compatible PC
PARALLEL PORT
Power inlet (required)
Power LED
ST SwitchPower Select Switch
(110V/220V)
Control Line
Not usedRS232C PARALLEL
V-SYNCPOWER
ST
VGSMONITOR
E
E
V-Sync On/Off Switch
(Switch must be ON.)F
F
A
A
BB
C
C
15
10
556 9
11
1
14 13
25 6
5V
5V5V
4.7K
4.7K
4.7K
74LS0674LS06 OFF ON
OFFON
11
RGB(PC/DTV) INANTENNA INAUDIO
(RGB) INH/P S-VIDEO
AV IN 2 AV 1(Mono)VIDEOAUDIOLR
Video Signal
Generator
Figure 1. Cable Connection 

ADC ADJUSTMENT
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1. DCXO setting in Video (AV2) 
■Convert to AV2 in Input-source
■Signal equipment display
Output Voltage : 700 mVp-p
Impress Resolution : NTSC J (Model No.207 at MSPG925L)
Pattern : Color Bar (Pattern No.33 ant MSPG925L)
1) IN-START selection of Service Remote Controller
2) OPTION4 Selection
3) Right button selection in DCXO-AUTO(AV2). 
Then, DCXO-AUTO may change from 0 to 1.
4) DCXO value confirmation 
(Exit and Enter again Option4 _ Menu+Option4 selection)
2. Video (AV2) input...

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3. RGB-PC input ADC
■Signal equipment display
Output Voltage : 730 mVp-p
Impress Resolution : SXGA (Model No.45 at MSPG925L)
Pattern : Gray pattern that left & right is black and center is white signal
(Pattern No.28 ant MSPG925L)
1) If Source change from AV2 to RGB-PC, Monitor executes auto intelligent.
Do not ADC In this condition.
2) Execute ADC after AC power off/on.
3) IN-START selection of Service Remote Controller
4) AUTOADC Selection
5) Right button selection in Auto Gain
Then, Value of...

TROUBLESHOOTING GUIDE
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No power 
(LED indicator off)
Check short of main B/D 
or Change Lips
Change U406
Change LED Assy
Check 15V or 5V 
of Lips
Check Output of 
U406
Check LED Assy
Check J103, J125, J126
Connector 
Fail
Fail
Change Q402Check Output of 
Q402
Fail
Pass
Pass
Fail
Pass
Pass
Pass
:[A]Process 

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No Raster
Check LED Status 
on display unit
Check the input/
Output of U301
Check 
U402, U403, U406
Check inverter
Connector or inverter
Check input source cable and jack
Repeat A PROCESSFail
Change U402, U403,
U406
Fail
Change U301Fail
Change inverter
connector or inverter
Fail
Change panel link
cable or module
Fail Check panel link 
Cable or module
Pass
Pass
Pass
Pass
Pass
:[B]Process 

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No Raster on AV Signal
(CVBS, S-VHS)No Raster on TV(RF) signal
Change L109, L110, L112 
R194, R198, R184Check the signal of 
L109, L110, L112
R194, R198, R184
Repeat
[A] Process Check the output of 
TU701
Check the
input/output  of U301
Check the 
input/output of U101
Check input source cable and
jack 
Fail
FailFail
Fail
Re-soldering or
Change the defect part
Check X301
Fail
Re-soldering or
Change the defect part
Check 5V, 33V of TU701
Re-soldering or 
Change the defect part
TN200
(TUNER PACK...

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No Sound
Check the speaker wire
Change source inputCheck the 
input source
Fail
Pass
Pass
Pass
Pass
Re-soldering or 
Change the defect part
Check X301Check the input/output 
of U301
Fail
Re-soldering or 
Change the defect partCheck the input/output 
of U201
Fail
Change speakerCheck the speakerFail 

WIRING DIAGRAM
- 20 -
30P
6631T11016M
5P11 P
6631T20038G
6631900042B
EAB32761501
3P
6631900024D