Samsung LE20S81BX User manual

TFT-LCD TV
Chassis GJA20SEU
Model LE20S81BX
Manual
SERVICE
TFT-LCD TV Fashion Feature
- Luxurious Slim Design
- Supreme Picture Quality
- Supreme Sound Quality
- Supreme Convenience Quality
- Convenience for Users

ii
Copyright
ⓒ2007 by Samsung Electronics Co., Ltd.
All rights reserved.
This manual may not, in whole or in part, be copied,
photocopied, reproduced, translated, or converted to any
electronic or machine readable form without prior
written permission of Samsung Electronics Co., Ltd.
LE26S81BX/LE32S81BX/LE37S81BX/LE40S81BX /
LE46S81BX Service Manual
First edition June 2007.
Printed in Korea.
Trademarks
Samsung is the registered trademark of Samsung
Electronics Co., Ltd.
LE26S81BX/LE32S81BX/LE37S81BX/LE40S81BX /
LE46S81BX and Macmaster Cable Adapter are
trademarks of Samsung Electronics Co., Ltd.
Macintosh and Power Macintosh are trademarks of
Apple Computer, Inc.
All other trademarks are the property of their respective
owners.

Contents
11. Precautions………………………………………………………………………………………………………………………………………11-1
1-1 Safety Precautions ……………………………………………………………………………………………………………………… 1-1
1-2 Servicing Precautions …………………………………………………………………………………………………………………… 1-2
1-3 Static Electricity Precautions …………………………………………………………………………………………………………… 1-2
1-4 Installation Precautions…………………………………………………………………………………………………………………… 1-3
2
2. Product specifications …………………………………………………………………………………………………………………………22-1
2-1 Fashion Feature…………………………………………………………………………………………………………………………… 2-1
2-2 LE26S81BX Specifications ……………………………………………………………………………………………………………… 2-2
2-3 LE32S81BX Specifications ……………………………………………………………………………………………………………… 2-3
2-4 LE37S81BX Specifications ……………………………………………………………………………………………………………… 2-4
2-5 LE40S81BX Specifications ……………………………………………………………………………………………………………… 2-5
2-6 LE46S81BX Specifications ……………………………………………………………………………………………………………… 2-6
2-7 Spec Comparison ………………………………………………………………………………………………………………………… 2-6
2-8 Option Specification ……………………………………………………………………………………………………………………… 2-7
3
3. Alignments and Adjustments …………………………………………………………………………………………………………………33-1
3-1 Service Instruction ……………………………………………………………………………………………………………………… 3-1
3-2 How to Access Service Mode …………………………………………………………………………………………………………… 3-2
3-3 Factory Data ……………………………………………………………………………………………………………………………… 3-3
3-4 Service Adjustment ……………………………………………………………………………………………………………………… 3-12
3-5 Software Upgrade ……………………………………………………………………………………………………………………… 3-15
4
4. Troubleshooting ………………………………………………………………………………………………………………………………44-1
4-1 First Checklist for Troubleshooting ………………………………………………………………………………………………………4-1
4-2 Checkpoints by Error Mode ……………………………………………………………………………………………………………… 4-2
5
5. Exploded View and Parts List …………………………………………………………………………………………………………………55-1
5-1 LE26S81BX Exploded View……………………………………………………………………………………………………………… 5-1
5-2 LE26S81BX Parts list …………………………………………………………………………………………………………………… 5-2
5-3 LE32S81BX Exploded View……………………………………………………………………………………………………………… 5-3
5-4 LE32S81BX Parts list …………………………………………………………………………………………………………………… 5-4
5-5 LE37S81BX Exploded View……………………………………………………………………………………………………………… 5-5
5-6 LE37S81BX Parts list …………………………………………………………………………………………………………………… 5-6
5-7 LE40S81BX Exploded View……………………………………………………………………………………………………………… 5-7
5-8 LE40S81BX Parts list …………………………………………………………………………………………………………………… 5-8
6
6. Electrical Parts List ……………………………………………………………………………………………………………………………66-1
6-1 LE26S81BX Parts List …………………………………………………………………………………………………………………… 6-1
6-2 LE32S81BX Parts List ………………………………………………………………………………………………………………… 6-22
6-3 LE37S81BX Parts List ………………………………………………………………………………………………………………… 6-38
6-4 LE40S81BX Parts List ………………………………………………………………………………………………………………… 6-55
7
7. Block Diagram …………………………………………………………………………………………………………………………………77-1

Contents
88. Wiring Diagram …………………………………………………………………………………………………………………………………88-1
8-1 LE26S81BX / LE32S81BX / LE37S81BX / LE40S81BX / LE46S81BX Wiring Diagram …………………………………………8-1
8-2 Main Board Layout ……………………………………………………………………………………………………………………… 8-2
8-3 PIN characteristic ………………………………………………………………………………………………………………………… 8-3
8-4 Power Board Layout ……………………………………………………………………………………………………………………… 8-6
99. Schematic Diagrams ……………………………………………………………………………………………………………………………99-1
10. O
Operating Instructions and Installation………………………………………………………………………………………………………110-1
10-1 Front …………………………………………………………………………………………………………………………………… 10-1
10-2 Connection Panel ……………………………………………………………………………………………………………………… 10-2
10-3 Remote control ………………………………………………………………………………………………………………………… 10-4
10-4 Installing the Stand …………………………………………………………………………………………………………………… 10-5
10-5 Installing the Wall Mount Kit ………………………………………………………………………………………………………… 10-5
1
11. Disassembly and Reassembly ………………………………………………………………………………………………………………111-1
11-1 Disassembly …………………………………………………………………………………………………………………………… 11-1
11-2 Reassembly …………………………………………………………………………………………………………………………… 11-5
1
12. PCB Diagram …………………………………………………………………………………………………………………………………112-1
13. CCircuit Descriptions ……………………………………………………………………………………………………………………………113-1
13-1 Block description ……………………………………………………………………………………………………………………… 13-1
13-2 Main Block ……………………………………………………………………………………………………………………………… 13-3
13-3 SMPS Board …………………………………………………………………………………………………………………………… 13-4
1
14. Reference Infomation ……………………………………………………………………………………………………………………… 114-1
14-1 Technical Terms ……………………………………………………………………………………………………………………… 14-1
14-2 Pin Assignments ……………………………………………………………………………………………………………………… 14-4
14-3 Timing Chart …………………………………………………………………………………………………………………………… 14-7
14-4 Panel Description …………………………………………………………………………………………………………………… 14-11

©2007 Samsung Electronics Co.,Ltd.
All rights reserved.
Printed in Korea
P/N : BN82-00245A-00
This Service Manual is a property of Samsung
Electronics Co.,Ltd.
Any unauthorized use of Manual can be punished under
applicable International and/or domestic law.
Area
GSPN(Global Service Partner Network)
North America
Latin America
CIS
Europe
China
Asia
Mideast & Africa
http://service.samsungportal.com
http://latin.samsungportal.com
http://cis.samsungportal.com
http://europe.samsungportal.com
http://china.samsungportal.com
http://asia.samsungportal.com
http://mea.samsungportal.com
Web Site

3 Alignments and Adjustments
3-1
3 Alignments and Adjustments
3-1 Service Instruction
1. Usually, a color TV-VCR needs only slight touch-up adjustment upon installation.
Check the basic characteristics such as height, horizontal and vertical sync.
2. Use the specified test equipment or its equivalent.
3. Correct impedance matching is essential.
4. Avoid overload. Excessive signal from a sweep generator might overload the front-end
of the TV. When inserting signal markers, do not allow the marker generator to distort
test result.
5. Connect the TV only to an AC power source with voltage and frequency as specified on
the backcover nameplate.
6. Do not attempt to connect or disconnect any wire while the TV is turned on. Make sure
that the power cord is disconnected before replacing any parts.
7. To protect aganist shock hazard, use an isolation transform.

3 Alignments and Adjustments
3-2
3-2 How to Access Service Mode
3-2-1 Entering Factory Mode
1. To enter “Service Mode” Press the remote -control keys in this sequence :
- If you do not have Factory remote - control
- If you have Factory remote - control
3-3 Factory Data
POWER OFF POWER ONMUTE 1 8 2
POWER ON INFO FACTORY
PC Auto Color
Video Auto Color
Reset
DLC/MWE Part
SFR PART
Sub Adjust
Adjust
Option
Checksum
Panel Information
Bus Stop : OFF
Service
2006/01/02
T-PLS23PEU-1002
-l
▶
▶
▶
▶
▶
▶
▶
▶
▶
▶
▶
Adjust
PC Auto Color
Option
Checksum
Panel Information
Reset
Bus Stop
Service Function
2005/04/20
TM-BRHMS20WW-0714
▶
▶
▶
▶
▶
▶
PC Auto Color
Video Auto Color
Reset
DLC/MWE Part
SFR PART
Sub Adjust
Adjust
Option
Checksum
Panel Information
Bus Stop : OFF
Service
2006/01/02
T-PLS23PEU-1002
▶
▶
▶
▶
▶
▶
▶
▶
▶
▶
▶
-. OSD which the basic adjustment is added.
PC Auto Color
Video Auto Color
Reset
DLC/MWE Part
SFR PART
Sub Adjust
Adjust
Option
Checksum
Panel Information
Bus Stop : OFF
*. 2005/06/23: MCU firmware date.
*. T-PLUS25NUS-0906: MCU firmware version information
(this information must be appended due to a compatibility problem report.)
1) Reset: Factory reset
2) Bus Stop: The communication Line ON / OFF
Move to the ( - ) / (+) key, select the 'Enter' key.
3) Auto adjustment
4) PC Auto Color/ Video Auto Color :in case that color
of all screen is wrong, excute the PC Auto color at
16 gray pattern(refer to attach left 16gray pattern)
5) Checksum: MCU firmware checksum information
(this information must be appended due to a compatibility problem report.)

3 Alignments and Adjustments
3-3
NVRAM Reset
▶
DLC- 0-10 0
MWE- 0-1 1
Demo 0-1 0
Brightness+ 0-255 100
Contrast+ 0-255 113
Sharpness+ -10-10 1
Hue+ 0-100 50
Saturation+ 0-255 125
R Offset 46
G Offset 50
B Offset 56
R Gain 58
G Gain 50
B Gain 51
DLC/MWE Part
DCXO Sel. 0
DCXO Tune 64
OVMADAPT 0-1 1
OVMTHR 0-3 2
IF Demod 0-63 38
F FI 0-1 0
R0:77 R1:71 R2:81
R3:18 R4:0 R5:1F
SFR Part
R Blk Lvl+ 0-63 28
G Blk Lvl+ 0-63 20
Peak Frq/DLY+0-3 0
Peak+ 0-63 40
Soft Clp Lvl- 0-3 0
W Limit- 0-15 8
R White Pnt+ 0-63 37
G White Pnt+ 0-63 31
B White Pnt+ 0-63 31
AGC T-O- 0-63 23
Sub Adjust
6) Dynamic Luma Adjustment
" - " : RF, AV, S_Video -> all store
" + " : RF, AV, S_Video -> apart store
7) Special Function Register

3 Alignments and Adjustments
3-4
BKS- 0-1 1
WSx- 0-3 2
0 0 0 0 0 20 20 2
0 20 20 20 20 20 20 20 2
0 20 20 20 19 26 …..
UOC Adjust
8) UOC Adjustment
BKS : Black stretch
Wsx : White stretch
9) Option: Spread Step / Spread Span (for EMI test )
10) Panel Information
various function are included in information.
- Monitor On Time : Power On Time
- Panel Cycle : Panel On/off time (Power off, Mode
change, DPMS on/off ...)
- Panel : Panel on Time
(when the panel is changed , select the Reset )
- Lower lamp : Lower lamp on time
(when the Lower lamp is changed , select the Reset )
- Upper lamp : Upper Lamp on time
(when the Upper Lamp is changed , select the Reset)

3 Alignments and Adjustments
3-5
3-4-1 EDID input method
3-4 Service Adjustment
3-4-2 EDID input method (Windows Program)
-SAMSUNG LCD TV support the DDC control JIG.
-You can see the connection between PC and LCD TV.
1. Execute "WinDDC.EXE"
2. Click "Open[F5]"

3 Alignments and Adjustments
3-6
3. Select Connected Port#1 and Click Next OK.
4. Select Connected Port#1 and Click Next OK.
Find file name : VC20
5. Click Next (OK) button.
6. Select enter button (on Key-Board) After Monitor S/N input .

3 Alignments and Adjustments
3-7
8. Check "DDC OK".
3-4-3 Micom ( TDA15001H) Program Upgrade
1. Program Upgrade Jig
2. Connect the parallel Port

3 Alignments and Adjustments
3-8
3. Connect Jig to CN905 on PCB Ass'y
4. Click " WISP " Icon on Computer
5. Check "Automatic mode on".
6. Click "Browser" button : Select the
Code , Click "Auto Execute" button
Check Erase and Write OK In "General"
window and check Verify OK in "ISP status"
window.

7 Block Diagrams
7-1
7 Block Diagram

Memo
7 Block Diagrams
7-2

13 Circuit Descriptions
13-1
13 Circuit Descriptions
13-1 Overall Block Structure

13 Circuit Descriptions
13-2
13-2-1 MAIN BOARD POWER TREE
13-2 Partial Block Description

13 Circuit Descriptions
13-3
13-2-2 WIRING DIAGRAM
CN402 CN906CN905
CN100
CN907CN600
CN100(9P) : To IP Board
CN402(50P) : To 20" Panel
CN905(5P) : To Program Download Jig
CN906(20P) : To Scart
CN600(3P) : Speaker
CN907(12P) : To Function Board

13 Circuit Descriptions
13-4

11 Disassembly and Reassembly
11-1
11 Disassembly and Reassembly
This section of the service manual describes the disassembly and reassembly procedures for the TFT-LCD
TV.
WARNING : This monitor contains electrostatically sensitive devices. Use caution when
handling these components.
11-1 Disassembly
Cautions : 1. Disconnect the monitor from the power source before disassembly.
2. Follow these directions carefully; never use metal instruments to pry apart the
cabinet.
Description Picture Description
1. Place monitor face down on cushioned table.
Remove screws from the rear cover.
Remove screws from the stand.