Samsung P2770HD, LS27EMDKU Schematic
LCD-Monitor
Chassis : LEM27DS
Model :
SERVICE
P2770HD
Manual
TFT-LCD Monitor Contents
1. Precautions
2. Product specications
3. Disassembly and Reassemble
4. Troubleshooting
5. Exploded View & Part List
6. Wiring Diagram
P2770HD
Refer to the service manual in the GSPN (see the rear cover) for the more information.
Contents
1. Precautions
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. Product specications
2-1. Feature & Specications ................................................................................................. 2-1
2-2. Spec Comparison to the Old Models .............................................................................. 2-3
2-3. Accessories .................................................................................................................... 2-4
3. Disassembly and Assembly
3-1. Disassembly ................................................................................................................... 3-1
4. Troubleshooting
4-1. First Checklist for Troubleshooting ................................................................................ 4-1
4-2. No Power ........................................................................................................................ 4-2
4-3. PC (ANALOG) No Screen ............................................................................................ 4-5
4-4. DVI No Screen ............................................................................................................... 4-8
4-5. HDMI No Screen .......................................................................................................... 4-10
4-6. Faults and Corrective Actions ....................................................................................... 4-13
4-7. Adjustment .................................................................................................................... 4-14
4-8. How to Access Service Mode ....................................................................................... 4-14
4-9. White Balance - Calibration .......................................................................................... 4-16
4-10. White Ratio (Balance) Adjustment ..............................................................................4-18
4-11. Servicing Information .................................................................................................. 4-19
5. Exploded View & Part List
5-1. Exploded View ................................................................................................................ 5-1
5-2. Parts List ......................................................................................................................... 5-3
6. Wiring Diagram
6-1. Wiring Diagram - Main Board ......................................................................................... 6-1
6-2. Wiring Diagram - Main Board ......................................................................................... 6-2
6-3. Connector Functions ...................................................................................................... 6-3
6-4. Cables ............................................................................................................................ 6-3
GSPN (Global Service Partner Network)
Area Web Site
North America http://service.samsungportal.com
Latin America http://latin.samsungportal.com
CIS http://cis.samsungportal.com
Europe http://europe.samsungportal.com
China http://china.samsungportal.com
Asia http://asia.samsungportal.com
Mideast & Africa http://mea.samsungportal.com
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.
© 2009 Samsung Electronics Co.,Ltd.
All rights reserved.
Printed in Korea
P/N: BN82-00807A-00
1. Precautions
1. Precautions
1-1. Safety Precautions
Follow these safety, servicing and ESD precautions to prevent damage and to protect against potential hazards such as
electrical shock.
1-1-1. Warnings
For continued safety, do not attempt to modify the circuit board.1.
Disconnect the AC power and DC power jack before servicing.2.
1-1-2. Servicing the LCD Monitor
When servicing the LCD Monitor, Disconnect the AC line cord from the AC outlet.1.
It is essential that service technicians have an accurate voltage meter available at all times. Check the calibration of 2.
this meter periodically.
1-1-3. Fire and Shock Hazard
Before returning the monitor to the user, perform the following safety checks:
Inspect each lead dress to make certain that the leads are not pinched or that hardware is not lodged between the 1.
chassis and other metal parts in the monitor.
Inspect all protective devices such as nonmetallic control knobs, insulating materials, cabinet backs, adjustment and 2.
compartment covers or shields, isolation resistorcapacitor networks, mechanical insulators, etc.
Leakage Current Hot Check (Figure 1-1): 3.
WARNING : Do not use an isolation transformer during this test.
Use a leakage current tester or a metering system that complies with American National Standards Institute (ANSI
C101.1, Leakage Current for Appliances), and Underwriters Laboratories (UL Publication UL1410, 59.7).
(READING SHOULD)
NOT BE ABOVE 0.5mA
DEVICE
UNDER
TEST
2-WIRE CORD
*ALSO TEST WITH
PLUG REVERSED
(USING AC ADAPTER
PLUG AS REQUIRED)
TEST ALL
EXPOSED METAL
SURFACES
LEAKAGE
CURRENT
TESTER
EARTH
GROUND
Figure 1-1. Leakage Current Test Circuit
With the unit completely reassembled, plug the AC line cord directly into a 120V AC outlet. With the unit’s AC switch 4.
rst in the ON position and then OFF, measure the current between a known earth ground (metal water pipe, conduit,
etc.) and all exposed metal parts, including: metal cabinets, screwheads and control shafts.
The current measured should not exceed 0.5 milliamp.
Reverse the power-plug prongs in the AC outlet and repeat the test.
1-1-4. Product Safety Notices
Some electrical and mechanical parts have special safetyrelated characteristics which are often not evident from visual
inspection. The protection they give may not be obtained by replacing them with components rated for higher voltage,
wattage, etc. Parts that have special safety characteristics are identied by on schematics and parts lists. A substitute
replacement that does not have the same safety characteristics as the recommended replacement part might create
shock, re and/or other hazards. Product safety is under review continuously and new instructions are issued whenever
appropriate.
1-1
1-2
1. Precautions
1-2. Servicing Precautions
WARNING: An electrolytic capacitor installed with the wrong polarity might explode.
Caution: Before servicing units covered by this service manual, read and follow the Safety Precautions section of
this manual.
Note: If unforeseen circumstances create conict between the following servicing precautions and any of the
safety precautions, always follow the safety precautions.
1-2-1 General Servicing Precautions
Always unplug the unit’s AC power cord from the AC power source and disconnect the DC Power Jack before 1.
attempting to:
(a) remove or reinstall any component or assembly, (b) disconnect PCB plugs or connectors, (c) connect a test
component in parallel with an electrolytic capacitor.
Some components are raised above the printed circuit board for safety. An insulation tube or tape is sometimes 2.
used. The internal wiring is sometimes clamped to prevent contact with thermally hot components. Reinstall all such
elements to their original position.
After servicing, always check that the screws, components and wiring have been correctly reinstalled. Make sure that 3.
the area around the serviced part has not been damaged.
Check the insulation between the blades of the AC plug and accessible conductive parts (examples: metal panels, 4.
input terminals and earphone jacks).
Insulation Checking Procedure: Disconnect the power cord from the AC source and turn the power switch ON. 5.
Connect an insulation resistance meter (500 V) to theblades of the AC plug.
The insulation resistance between each blade of the AC plug and accessible conductive parts (see above) should be
greater than 1 megohm.
Always connect a test instrument’s ground lead to the instrument chassis ground before connecting the positive lead; 6.
always remove the instrument’s ground lead last.
1-3. Static Electricity Precautions
Some semiconductor (solid state) devices can be easily damaged by static electricity. Such components are commonly
called Electrostatically Sensitive Devices (ESD). Examples of typical ESD are integrated circuits and some eld-effect
transistors. The following techniques will reduce the incidence of component damage caused by static electricity.
Immediately before handling any semiconductor components or assemblies, drain the electrostatic charge from your 1.
body by touching a known earth ground. Alternatively, wear a discharging wrist-strap device. To avoid a shock hazard,
be sure to remove the wrist strap before applying power to the monitor.
After removing an ESD-equipped assembly, place it on a conductive surface such as aluminum foil to prevent 2.
accumulation of an electrostatic charge.
Do not use freon-propelled chemicals. These can generate electrical charges sufcient to damage ESDs.3.
Use only a grounded-tip soldering iron to solder or desolder ESDs.4.
Use only an anti-static solder removal device. Some solder removal devices not classied as “anti-static” can generate 5.
electrical charges sufcient to damage ESDs.
Do not remove a replacement ESD from its protective package until you are ready to install it. Most replacement ESDs 6.
are packaged with leads that are electrically shorted together by conductive foam, aluminum foil or other conductive
materials.
Immediately before removing the protective material from the leads of a replacement ESD, touch the protective 7.
material to the chassis or circuit assembly into which the device will be installed.
Caution: Be sure no power is applied to the chassis or circuit and observe all other safety precautions.
Minimize body motions when handling unpackaged replacement ESDs. Motions such as brushing clothes together, 8.
or lifting your foot from a carpeted oor can generate enough static electricity to damage an ESD.
1-3
1. Precautions
1-4. Installation Precautions
For safety reasons, more than two people are required for carrying the product.1.
Keep the power cord away from any heat emitting devices, as a melted covering may cause re or electric shock.2.
Do not place the product in areas with poor ventilation such as a bookshelf or closet. The increased internal 3.
temperature may cause re.
Bend the external antenna cable when connecting it to the product. This is a measure to protect it from being exposed 4.
to moisture. Otherwise, it may cause a re or electric shock.
Make sure to turn the power off and unplug the power cord from the outlet before repositioning the product. Also check 5.
the antenna cable or the external connectors if they are fully unplugged. Damage to the cord may cause re or electric
shock.
Keep the antenna far away from any high-voltage cables and install it rmly. Contact with the highvoltage cable or the 6.
antenna falling over may cause re or electric shock.
When installing the product, leave enough space (10cm) between the product and the wall for ventilation purposes. 7.
A rise in temperature within the product may cause re.
1. Precautions
Memo
1-4
2. Product specications
2. Product specications
2-1. Feature & Specications
Feature
Supreme Digital Interface & Networking ሪ
- With a built-in HD digital tuner, it supports HD broadcasting with no particular set-top box and provides simple
access with a single remote control.
Excellent Picture Quality ሪ
Dynamic Contrast ሪ
- Automatically detects the input visual signal and adjusts to create optimum contrast.
DTV Tuner, HDMI, Stereo, Dolby Digital support ሪ
Convenience ሪ
-The TV utilizes the HDMI system to implement perfect digital sound and picture quality.
Specications
Item Description
Model P2770HD
LCD Panel TFT-LCD Panel, RGB Vertical stripe, normally White,
27-Inch viewable, 0.3114(H) X 0.3114(V) mm Pixel Pitch
Scanning Frequency Horizontal : 30 kHz ~ 81 kHz (Automatic)
Vertical: 56 Hz ~ 75 Hz(Automatic)
Display Colors 16.7 Million colors
Maximum resolution
Input Signal Analog 0.7 Vp-p ±5% positive at 75Ω, internally terminated
Input Sync Signal Type : Seperate H/V
Maximum Pixel Clock rate 138.5 MHz
Active Display
(Horizontal/Vertical)
AC power voltage &
Frequency
Power Consumption 51W ＜ 2W
Dimensions Set
(W x H x D)
Weight Set
(After installation Stand)
TV System Tuning : Frequency Synthesize
667.0mm X 422.0mm X 66.0mm (Without Stand)
667.0mm X 484.0mm X 244.0 mm (With Stand)
Horizontal: 1920pixels
Vertical: 1080pixels
Level : TTL level
597.89(H) X 336.31(V)
AC 110 ~ 240V, 50 ~ 60 Hz
8.2kg (Product) / 11.8kg (Packing)
Environmental
Considerations
System : PAL,NTSC443, SECAM
Sound : MONO, STEREO, NICAM
Operating Temperature: 50˚C ~ 104˚F(10˚C ~ 40˚C)
Operating Humidity : 10% ~ 80%
Storage Temperature: -4˚C ~ 113˚C(-20˚C ~ 45˚C)
Storage Humidity: 5% ~ 95%
2-1
2-2
2. Product specications
Specications
Item Description
Model P2770HD
Antenna Input 75Ω
Sound Characteristic -MAX Internal speaker Out : Right : 3W / Left : 3W
-BASS Control Range : -8 dB ~ + 8dB
-TREBLE Control Range : -8 dB ~ +8 dB
-Headphone Out : 10 mW MAX
-Output Frequency : RF : 80 Hz ~ 15 kHz
A/V : 80 Hz ~ 20 kHz
2-3
2. Product specications
2-2. Spec Comparison to the Old Models
Model
Design
Screen Size 27” 23”
Resolution 1920X1080 (FHD) 60Hz 1920X1080 (FHD) 60Hz
Brightness 300cd/m2 300cd/m2
Contrast Ratio 1000:1 1000:1
Response Time 5ms 5ms
Viewing Angle Left/Right/Up/Down : 80˚/80˚/80˚/80˚ Left/Right/Up/Down : 80˚/80˚/80˚/80˚
PC Input D-SUB, DVI D-SUB, DVI
Ecot-MFM
P2770HD
CREAM-MFM
2333HD
Power Consumption 51W 54W
DPMS Less than 2W Less than 2W
Sound Output 3W x 2 3W x 2
Dynamic Contrast Ratio 50000:1 10000:1
Sound Effect
Image Size : If the resolution is not wide resolution, this option allows the screen size to be selected as normal or wide.
Dolby Digital Plus,
SRS TruSurround HD
Dolby Digital
2. Product specications
2-3. Accessories
Product Description Ccde. No Remark
Remote Control
&
Batteries (AAA x 2)
Power Cord 3903-000452
Stand Body BN96-09628C
Stand Base BN96-11315A
BN59-00865A
Samsung Electronics
Service center
D-Sub Cable BN39-00244G
User’s Guide,
Monitor Driver,
Natural Color Pro Software
Cleaning Cloth BN63-01798B
Holder-Cable BN96-06529A
BN59-00910C
2-4
3. Disassembly and Assembly
3. Disassembly and Assembly
This section describes the disassembly and reassembly sequences for this monitor.
Warning: As this monitor has parts that are sensitive to static electricity, be careful when handling them.
3-1. Disassembly
Caution: 1. Turn the monitor off before beginning the disassembly process.
2. When disassembling the monitor, do not use any metal tools except for the provided jig.
3. Remove the signal cable and the power cord before beginning the disassembly.
Description Photo Screws
1. Place the monitor face downwards on a soft
blanket or cushion as shown in the picture on
the right. Move the stand from side to side to
disassemble it.
Caution : Do not disassemble with excessive
force. This may break the transparent
stand-bar.
2. Remove the two (2) screws at the bottom.
3-1
3-2
3. Disassembly and Assembly
Description Photo Screws
3. Hold the Front-Cover by its corners and push
it downwards. In the same manner, push down
on the other corners, lift the Rear-Cover, and
disassemble it as shown in the picture below.
3-3
3. Disassembly and Assembly
Description Photo Screws
4. After disassembling the Rear-Cover, prepare for
the internal disassembly as shown in the picture
on the right.
5. Remove the LVDS cable.
LAMP WIRE
LVDS
Function &
SPK Wire
6. Remove the Lamp wire.
7. Remove the Function & SPK wires.
3. Disassembly and Assembly
Description Photo Screws
8. Remove the SPK upwards.
9. Remove the Assy Shield-Cover.
Disassemble the PCB inside the Assy.
10. Remove the Holder-Boss from the Assy FrontCover.
Caution : It is difcult disassembling the panel
without removing the screws.
Make sure to remove the screws before
removing the Holder-Boss.
11. Disassemble the panel.
※ Reassembly procedures are in the reverse order of disassembly procedures.
3-4
4. Troubleshooting
4. Troubleshooting
4-1. First Checklist for Troubleshooting
Self-Test Feature Check
Your monitor provides a self test feature that allows you to check whether your monitor is functioning properly.
Turn off both your computer and the monitor. 1.
Unplug the video cable from the back of the computer2.
Turn on the monitor. 3.
If the monitor is functioning properly, you will see a box in the illustration below. .
This box appears during normal operation if the video cable becomes disconnected or damaged.
4. Turn off your monitor and reconnect the video cable; then turn on both your computer and the monitor.
If your monitor screen remains blank after using the previous procedure, check your video controller and
computer system; your monitor is functioning properly.
Warning Messages
If there is something wrong with the input signal, a message appears on the screen or the screen goes blank although the
power indicator LED is still on. The message may indicate that the monitor is out of scan range or that you need to check
the signal cable.
Environment
The location and the position of the monitor may inuence the quality and other features of the monitor.
If there are any sub woofer speakers near the monitor, unplug and relocate the woofer to another room.
Remove all electronic devices such as radios, fans, clocks and telephones that are within 3 feet (one meter) of the monitor.
Useful Tips
▶ A monitor recreates visual signals received from the computer.
Therefore, if there is trouble with the computer or the video card, this can cause the monitor to become blank,
have poor coloring, noise, Video mode not supported, etc. In this case, rst check the source of the problem,
and then contact the Service Center or your dealer.
▶ Judging the monitor’s working condition
If there is no image on the screen or a “Not Optimum Mode”, “Recommended Mode 1920 X 1080 60Hz” message
comes up, disconnect the cable from the computer while the monitor is still powered on.
- If there is a message coming up on the screen or if the screen goes white, this means the monitor is in working
condition.
- In this case, check the computer for trouble.
4-1
4-2
4. Troubleshooting
4-2. No Power
Symptom
Major
checkpoints
The LED on the front panel of the monitor does not work when the power is connected and the Power button is pressed.
Check if the Power switch on the rear panel of the monitor has been turned on. -
Check the SMPS fuse and the IP-Board output power. -
Check the connection between the IP-Board and the Main Board inside the monitor. -
Check the power part of the Main Board and check if a similar symptom appears at another output terminal.
CN1001
IC1023
IC4010
Diagnostics
Does proper 14.5V appear at pin
No. 2 of CN1001? ①
Does proper 5V appear at pin No.
6 and 7 of CN1001? ②
Yes
Does proper 14.5V appear at
BD1013? ①
Does proper 5V appear at
BD1021? ②
Yes
Does proper 3.3V appear at pin
No.1 of IC1024? ②
Yes
Does proper 14.5V appear at
IC1023? ③
Yes
Change main board for
Scaler(IC4010) problem
Main Board Front
No
No
No
No
Check IP Board
Check related circuit of CN1001.
Check related circuit of IC1024.
Check related circuit of IC1022.
Caution Make sure to disconnect the power before working on the IP board.
4-3
4. Troubleshooting
4-2-1. Circuit diagrams when the power does not turn on
4-4
4. Troubleshooting
4-2-2. Waveforms
①
②
③
4-5
4. Troubleshooting
4-3. PC (ANALOG) No Screen
Symptom
Major
checkpoints
The LED power is on but no picture is displayed on the screen when the D-SUB cable is connected
Even though the LED power turns on, the screen is blank when connecting the VGA cable. -
Check the D-sub cable connections. -
Check whether the LVDS cable is connected correctly to the panel. -
Check whether the lamp connector of the panel is connected correctly to the IP board. -
CN1005
CN8003
Main Board Front
Diagnostics
Caution Make sure to disconnect the power before working on the IP board.
Does led persists green light after
power on?
Yes
Does proper 5V appear at pin No.
9 of CN8003?
Yes
Does proper V-sync ④ and H-sync
⑤ appear at C809 and C808?
Yes
Does proper clock signals appear
at pin NO.11,12,23,24 of CN1005?
Yes
Check connection between main
board and panel.
Change Panel.
No
No
No
No
Check IP board
Check D-sub cable connection
Check PC state
Change main board
because of scaler problem
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