Daewoo DLT-20W2 User manual

Service Manual
20" LCD
CHASSIS :
Model :
S/M NO. : DSL140TEF0
SL-140T
DLT-20W2
Jul. 2007

Contents
I. Parts with the exception of MODULE
1. Safety Precaution⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯ 3
2. Product Specification ⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯ 4
3. Block Diagram ⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯ 5
4. Schematic Diagram⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯ 8
5. PCB Data ⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯ 16
6. Trouble Shooting ⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯ 18
7. Service Part List ⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯ 26
7-1 Service Part List ⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯ 26
9. Power ⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯ 31
10. Inverter ⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯ 32
11. Out Line ⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯ 34
12. Exploded View ⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯ 35
SOFTWARE INSTALL & UPGRADE
-2-

-3-
1. Safety Precautions
(1) When moving or laying down a LCD Set, at least two people must work together. Avoid any
impact towards the LCD Set.
(2) Do not leave a broken LCD Set on for a long time. To prevent any further damages, after
checking the condition of the broken Set, make sure to turn the power (AC) off.
(3) When opening the BACK COVER, you must turn off power (AC) to prevent any electric
shock.
(4) When loosening screws, check the position and type of the screw. Sort out the screws and
store them separately for reassembling. Because screws holding PCBs are working as
electric circuit grounding, make sure to check if any screw is missing when assembling /
reassembling. Do not leave any screws inside the set.
(5) A LCD Set contains different kinds of connector cables. When connecting or disconnecting
cables, check the direction and position of the cable beforehand.
(6) Connect/disconnect the connectors slowly with care especially FFC (film) cables and FPC
cables. Do not connect or disconnect connectors instantaneously with force, and handle
them carefully for reassembling.
(7) Connectors are designed so that if the number of pins or the direction does not match,
connectors will not fit. When having problem in plugging the connectors, check their kind,
position, and direction.

-5-
3. Block Diagram
Tuner
TD1318
IF Filter (SAW)
[K3953M] [K9650M]
LOC-II
<Front End>
LOC-II
<Back End>
S
C
A
R
T
Digital Block
A V
2
C
O
M
P
D
S
U
B
H D
M
I
KEY
Circuit
REMOCON
Circuit
I302
EEPROM
I503
Flash Memory
LCD PANEL
HDMI
TDA9973
IA03
Audio Switch
IA05
Video
Switch
Inverter
Power
I603
H/P AMP
I601
AUDIO AMP
5V_Clean
IF
VIF SIF SAWS/W
AGC, AGC_ADJ
R, G, B, CVBS AUDIO L/R
TS SCART IN [R/G/B/FB, L/R, Vin] SCART OUT [Vout, L/R]
S/SW
UOC_UP, SCALAR_UP
Front AV, S-VHS IN [V, Y, C] Front AUDIO IN [L/R]
HDMI IN
D VIDEO L/R R, G, B
SPDIF OUT COMP AUDIO IN[L/R] COMP Video IN [Y, Pb, Pr]
PC IN [R, G, B] PC AUDIO IN [L/R]
IIC
KEYB IR HP L/R Out MAIN L/R Out
/RST, /WR, /OE LVDS BL-EN, BL_ADJ
L/R
LED
Address[0:17] Data[0:8]
2
8
4 2 7 3 2
2
8
3 2
24
2
2 3 3 2
3 2
2
2 2
16 3 10 2
2
PC Hsync, Vsync
8
SW
SW

-6-
Block Diagram
CI Control
ICD30
CIMAX
CI SLOT
PI01
MPEG
PNX8314 SDRAM
K4S281632D
Flash
Memory
M29W320
Latch
74LVC573
BUS
Transceiver
74LVC245
EEPROM
M24C64
ADC
UDA1334BTS
A_MDI[0:7]
A_MDO[0:7]
PCMCIA[0:7]
PCMCIA_D[0:7]
TS_DATA[0:7] MIU_DATA[0:7] MIU_ADDR[0:24]
TDA_Data[0:7]
SDRAM_DATA[0:15] SDRAM_ADDR[0:14]
R, G, B, CVBS
DVB AUDIO L/R
IIC IIS
Latch
74LVC573
TS_Valid TS_Sync TS_CLK
PCMCIA[8:14]
88
8 24
815
87
22
4 2
16 15

-7-
Block Diagram
POWER
MODULE
INVERTER
I804
AP1117EA33A
S/B 3.3V
SW8
MAIN SW
I803
IRF7316
Channel #1
9V Switching
Channel #2
5V Switching
I851
APW1172
9V 3.3V
I806 (LM317)
9V 5V
I808 (LM317)
9V 5V
I809(AP1117E18A)
3.3V 1.8V
I812(AP1117E18A)
3.3V 1.8V
I821(AP1117E33A)
5V 3.3V
I822(AP1117E18A)
5V 1.8V
I853(APW1172)
5V 1.2V
I805
IRF7316
Channel #1
15V Switching
Channel #2
PA NEL Power
Switching
TUNER
ICD12
I501(LOCII)
IA03, IA05,
EEPROM, Etc
I305(HDMI) I305(HDMI)
ICD02
I501(LOC II)
ICD13
I601
PA NEL
AUO 20 INCH
24V
BL_EN BL_ADJ

4. Schematic Diagram
-8-

-9-
Schematic Diagram

Schematic Diagram
-10-

Schematic Diagram
-11-

Schematic Diagram
-12-

Schematic Diagram
-13-

-14-
Schematic Diagram

-15-
Schematic Diagram

6. PCB Data
-16-
TOP

PCB Data
-17-
BOTTOM

-18-
7. Trouble Shooting
* Facts you must know at trouble diagnosis or repairing
(1) The trouble diagnosis and repairing of set means Module .
In other words, find out which PCB modules are not working and replace them with normal
PCB modules.
(2) This TROUBLE SHOOTING list only contains representative and simple PCB trouble
diagnosis and Module Exchange method. Therefore, if you find Sets which are difficult to
diagnose or to repair, contact Daewoo Electronics.
(3) Basic TROUBLE SHOOTING procedure :
Check Trouble Symptoms →Detach Back Cover →Trouble Diagnosis →Replace broken
PCB module →Adjust white balance →Function Check →Repair Complete.
(4) Required equipments for trouble diagnosis
- Digital Multi-meter (measure Dc voltage, measure Diode Voltage, Short-Open test)
- Screwdriver (or electric screwdriver), plastic adjusting tool
(5) Before assemble/disassemble PCBs, check to see if AC Switch is OFF.
(6) After Back cover is closed, redo Heat-run for at least one hour by inputting Full white
pattern.
Symptoms of power, inverter, panel Trouble
<Symptom.1> Not even weak discharge (luminescence) shows on screen.
<Symptom.2> Discharge (luminescence) on screen is unstable
<Symptom.3> Set is producing unusual noise
Symptoms of VIDEO or JACK PCB Trouble
<Symptom.1> Only weak discharge (luminescence) shows on screen, but No Data is on
screen
<Symptom.2> Screen DATA is abnormal
<Symptom.3> Particular input signal (Video, etc.) does not operate
<Symptom.4> No SOUND
<Symptom.5> Remote Control or KEY does not operate

-19-
Trouble Shooting
7-1. When LED doesn’t lit.
Is the AC power cord
correctly connected?
Is power S/W ON?
Is output voltage of
Power module correct?
(or LIPS)
Confirm power cord
connection.
Confirm Power S/W ON.
Check the power connection.
Exchange the power module.
Check start
Y
N
N
N
Y
Y
Y
Check the Main PCB.

-20-
Trouble Shooting
7-2. When TV doesn’t turn on in red LED.
Does TV turn on
pushing the CH key? Check the power connection.
Exchange the Power module.
Confirm Power S/W ON.
Check the connection to IR PCB.
Check the operation of Remote
Controller.
Check start
Y
N
N
Y
Is output voltage of
Power module correct?
(or LIPS)
Y
7-3. When “white screen”.
Is normal?
Check the Main PCB
Check start
Y
N
Y
Is correctly
connected? Check the connection
Of Panel
N
Y
Check the connector or Main PCB