Samsung 2494HS, 2494HSI, 2494HM Service manual

LCD-Monitor

Chassis : LS24KI

Model : 2494HS

2494HSI

2494HM

SERVICE Manual

TFT-LCD Monitor		Contents

1. Precautions

2. Product specifications

3. Disassembly and Reassemble

4. Troubleshooting

5. Exploded View & Part List

6. Wiring Diagram

7. Schematic Diagram

2494HS / 2494HSI / 2494HM

Refer to the service manual in the GSPN (see the rear cover) for the more information.

	Contents
1.	Precautions...............................................................................................................	1-1
	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.	Product specifications.............................................................................................	2-1
	2-1. Feature & Specifications.................................................................................................	2-1
	2-2. Spec Comparison to the Old Models...............................................................................	2-2
	2-3. Accessories.....................................................................................................................	2-3
	2-4. Accessories (Sold separately).........................................................................................	2-3
3.	Disassembly and Reassemble................................................................................	3-1
	3-1. Disassembly (2494HS)....................................................................................................	3-1
	3-2. Disassembly (2494HS)....................................................................................................	3-3
4.	Troubleshooting.......................................................................................................	4-1
	4-1. Troubleshooting...............................................................................................................	4-1
	4-2. When the Power Does Not Turn On................................................................................	4-2
	4-3. When a blank screen is displayed (Analog)....................................................................	4-4
	4-4. When a Blank Screen Is Displayed (DVI) .......................................................................	4-7
	4-5. Error Examples and Actions..........................................................................................	4-10
	4-6. Adjustment.....................................................................................................................	4-11
5.	Exploded View & Part List.......................................................................................	5-1
	5-1. Exploded View (2494HS)................................................................................................	5-1
	5-2. Parts List (2494HS).........................................................................................................	5-3
	5-3. Exploded View (2494HM)..............................................................................................	5-15
	5-4. Parts List (2494HM)......................................................................................................	5-17
6.	Wiring Diagram.........................................................................................................	6-1
	6-1. Wiring Diagram - Main Board..........................................................................................	6-1
	6-2. Wiring Diagram................................................................................................................	6-2
	6-3. Connector Functions.......................................................................................................	6-3
	6-4. Cables.............................................................................................................................	6-3
7.	Schematic Diagram..................................................................................................	7-1
	7-1. Circuit Descriptions.........................................................................................................	7-1
	7-2. Schematic Diagram ........................................................................................................	7-3

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.

© 2008 Samsung Electronics Co.,Ltd. All rights reserved.

Printed in Korea

P/N: BN82-00507A-01

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

1.For continued safety, do not attempt to modify the circuit board.

2.Disconnect the AC power and DC power jack before servicing.

1-1-2. Servicing the LCD Monitor

1.When servicing the LCD Monitor, Disconnect the AC line cord from the AC outlet.

2.It is essential that service technicians have an accurate voltage meter available at all times. Check the calibration of this meter periodically.

1-1-3. Fire and Shock Hazard

Before returning the monitor to the user, perform the following safety checks:

1.Inspect each lead dress to make certain that the leads are not pinched or that hardware is not lodged between the chassis and other metal parts in the monitor.

2.Inspect all protective devices such as nonmetallic control knobs, insulating materials, cabinet backs, adjustment and compartment covers or shields, isolation resistorcapacitor networks, mechanical insulators, etc.

3.Leakage Current Hot Check (Figure 1-1):

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

				LEAKAGE
DEVICE
				CURRENT
UNDER
				TESTER
TEST
	TEST ALL
	EXPOSED METAL
	SURFACES
2-WIRE CORD

*ALSO TEST WITH
PLUG REVERSED
(USING AC ADAPTER
PLUG AS REQUIRED)	EARTH
	GROUND	Figure 1-1. Leakage Current Test Circuit

4.With the unit completely reassembled, plug the AC line cord directly into a 120V AC outlet. With the unit’s AC switch first 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 identified 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, fire and/or other hazards. Product safety is under review continuously and new instructions are issued whenever appropriate.

1-1

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 conflict between the following servicing precautions and any of the safety precautions, always follow the safety precautions.

1-2-1 General Servicing Precautions

1.Always unplug the unit’s AC power cord from the AC power source and disconnect the DC Power Jack before 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.

2.Some components are raised above the printed circuit board for safety. An insulation tube or tape is sometimes used. The internal wiring is sometimes clamped to prevent contact with thermally hot components. Reinstall all such elements to their original position.

3.After servicing, always check that the screws, components and wiring have been correctly reinstalled. Make sure that the area around the serviced part has not been damaged.

4.Check the insulation between the blades of the AC plug and accessible conductive parts (examples: metal panels, input terminals and earphone jacks).

5.Insulation Checking Procedure: Disconnect the power cord from the AC source and turn the power switch ON.

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.

6.Always connect a test instrument’s ground lead to the instrument chassis ground before connecting the positive lead; 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 field-effect transistors. The following techniques will reduce the incidence of component damage caused by static electricity.

1.Immediately before handling any semiconductor components or assemblies, drain the electrostatic charge from your 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.

2.After removing an ESD-equipped assembly, place it on a conductive surface such as aluminum foil to prevent accumulation of an electrostatic charge.

3.Do not use freon-propelled chemicals. These can generate electrical charges sufficient to damage ESDs.

4.Use only a grounded-tip soldering iron to solder or desolder ESDs.

5.Use only an anti-static solder removal device. Some solder removal devices not classified as “anti-static” can generate electrical charges sufficient to damage ESDs.

6.Do not remove a replacement ESD from its protective package until you are ready to install it. Most replacement ESDs are packaged with leads that are electrically shorted together by conductive foam, aluminum foil or other conductive materials.

7.Immediately before removing the protective material from the leads of a replacement ESD, touch the protective 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.

8.Minimize body motions when handling unpackaged replacement ESDs. Motions such as brushing clothes together, or lifting your foot from a carpeted floor can generate enough static electricity to damage an ESD.

1-2

1. Precautions

1-4. Installation Precautions

1.For safety reasons, more than two people are required for carrying the product.

2.Keep the power cord away from any heat emitting devices, as a melted covering may cause fire or electric shock.

3.Do not place the product in areas with poor ventilation such as a bookshelf or closet. The increased internal temperature may cause fire.

4.Make sure to turn the power off and unplug the power cord from the outlet before repositioning the product. Also check the antenna cable or the external connectors if they are fully unplugged. Damage to the cord may cause fire or electric shock.

5.Keep the antenna far away from any high-voltage cables and install it firmly. Contact with the highvoltage cable or the antenna falling over may cause fire or electric shock.

6.When installing the product, leave enough space (10cm) between the product and the wall for ventilation purposes.

A rise in temperature within the product may cause fire.

1-3

1. Precautions

Memo

1-4

2. Product specifications

2. Product specifications

2-1. Feature & Specifications

Model	2494HS / 2494HSI / 2494HM

Feature

Support PC / DVI / HDMI

DC DC 50000:1 Applied

Adopted two 3W speakers.

USB (1 up, 2 down) optional

HDCPApplied for HDMI/DVI-D Fixed Aspect Ratio Support

Supports fixed horizontal and vertical ratios

Supported camera effects: Black/Sepia/Green/Blue

Supports the Off-timer function

Specifications

Item	Description
Model	2494HS / 2494HSI	2494HM
LCD Panel	TFT-LCD panel, RGB vertical stripe,	TFT-LCD panel, RGB vertical stripe,
	normally black transmissive,	normally black transmissive,
	23.6-Inch viewable, 0.2715(H)x0.2715(V)	24-Inch viewable, 0.2768(H)x0.2768(V)
	mm pixel pitch	mm pixel pitch
Scanning Frequency	Horizontal: 30 kHz ~ 81 kHz (Automatic)
	Vertical: 56 Hz ~ 60 Hz
Maximum Resolution	Horizontal: 1920 Pixels
	Vertical: 1080 Pxels
Input Signal	PC/DVI/HDMI
Input Sync Signal	Seperate H/V sync, Composite:
	automatic synchronization without external switch
	Level : TTL level (V high ≥ 2.0V, V low ≤ 0.8V)
Maximum Pixel Clock Rate	164MHz
Active Display Horizontal/Vertical	521.28(H) x 293.22(V) mm	531.36(H) x 298.89(V) mm
AC Power Voltage & Frequency	AC 90~264V Volts, 60/50Hz
Power Consumption	Less than 48W	Less than 48W
Dimensions ( W X H X D)	572.8 x 227.4 x 420.4 mm (With Stand)	572.8 x 249.9 x 420.4 mm (With Stand)
	572.8 x 67.5 x 363.4 mm (Without Stand)	572.8 x 67.5 x 363.7 mm (Without Stand)
Weight	Products: 6.2 kg	Products: 8.4 kg
Environmental	Operating Temperature: 10˚C ~ 40˚C(50˚F ~ 104˚F)
Considerations	Operating Humidity: 10% ~ 80%
	Storage temperature: -20˚C ~ 45˚C(-4˚F ~ 113˚F)
	Storage Humidity: 5% ~ 95%

Note: Designs and specifications are subject to change without prior notice..

2-1

2. Product specifications

2-2. Spec Comparison to the Old Models

Model

Design

Screen Size

Display Size

Brightness

Dynamic CR

Input Source

Speaker

Magictune

Gamma

MagicBright

Color Tone

2494HS / 2494HSI

2494HM

2493HM

23.6”		24”		24”
16:9	16:9		16:10
300cd/m2		300cd/m2		400cd/m2
50000:1	50000:1		10000:1
Analog/Digital/HDMI		Analog/Digital/HDMI		Analog/Digital/HDMI
3Wx2		3Wx2		2Wx2
Premium		Premium		Premium
3 steps		3 steps		3 steps
Mode1 / Mode2 / Mode3		Mode1 / Mode2 / Mode3		Mode1 / Mode2 / Mode3
7 steps (Text / Internet / Game		7 steps (Text / Internet / Game		7 steps (Text / Internet / Game
/ Sports / Movie / Dynamic CR /		/ Sports / Movie / Dynamic CR /		/ Sports / Movie / Dynamic CR /
Custom)		Custom)		Custom)
4 Step		4 Step		4 Step
Cool / Normal / Warm / Custom		Cool / Normal / Warm / Custom		Cool / Normal / Warm / Custom

2-2

			2. Product specifications
2-3. Accessories
Product	Description	Ccde. No	Remark
	Quick Setup Guide	BH68-00174P
	Warranty Card	BH68-01146A
	(Not available in all locations)
	User’s Guide,
	Monitor Driver,	BN59-00660F	Samsung Electronics
	Natural Color software,
	MagicTune™ software		Service center
	D-Sub(15 Pin) Cable	BN39-00244G
	(Shipped as assembled with the set)
	Power Cord	3903-00212
	USB Cable(USB HAS stand only)	BN39-00397C
2-4. Accessories (Sold separately)
Product	Description	Ccde. No	Remark
	DVI Cable	BN39-00246K	Samsung Electronics
			Service center

2-3

2. Product specifications

Memo

2-4

3. Disassembly and Reassemble

3. Disassembly and Reassemble

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 (2494HS / 2494HSI)

Cautions: 1. Turn the monitor off before beginning the disassembly process.
2.	Disassemble the monitor carefully as directed in the following procedures.
3.	When disassembling the monitor, do not use any metal tools except for the provided jig.
Part	Description	Picture Description	Screws

1.Place a soft cloth on the table and place the monitor on it so the front part is facing downwards. Hold and pull the stand downwards to remove it from the monitor set.

Stand

2.Remove the four (4) screws on the bottom, as shown in the figure on the right.

3.Hold the projected part of the rear cover with one hand, hold the front cover with the other hand, and then lift and remove the rear cover upwards.

	Caution : If you remove the rear
	cover by holding and lifting
Rear cover	the red circle part marked
	with ‘NO’ upwards (to the
	left of the figure on the	NO			YES
	right), a crack may occur
	on the Function-PCB
	connector. Make sure to
	hold and lift the red circle
	part marked with ‘YES’
	upwards (to the right of
	the figure on the right), to					If handled
	remove the rear cover.
						incorrectly,
						a crack may
						occur on the
						Function-PCB
						connector.

3-1

3. Disassembly and Reassemble

Part

Description

Picture Description

Screws

4. Remove the shield lamp using a flat

SHIELD- screwdriver or the provided jig.

LAMP Caution : Be careful because the shield lamp is sharp.

	Removing	5. Remove the lamp wire, function wire,
		speaker connector, and LVDS cable
	the cables
		connected to the chassis.

	ASSY	6. Remove the four (4) hex screws on
		the bottom of the shield, as shown in
	CHASSIS
		the figure on the right.

7.Remove the eight (8) screws designated in the figure on the right,

lift the boards upwards and remove the cable shown in the figure on the right.

MAIN

BOARD,

IP-Board

8.Remove the main board and IP-board from the shield cover.

3-2

3. Disassembly and Reassemble

3-2. Disassembly (2494HS)

Cautions: 1. Turn the monitor off before beginning the disassembly process.

2.Disassemble the monitor carefully as directed in the following procedures.

3.When disassembling the monitor, do not use any metal tools except for the provided jig.

Part

Description

Picture Description

Screws

1.Place a soft cloth on the table and place the monitor on it so the front part is facing downwards.

Remove the four (4) screws designated in the figure on the right and remove the stand.

Caution : When removing the screws, make sure to hold the stand body with one hand so that the stand does not fall over.

Stand

2.Remove the four (4) screws on the bottom, as shown in the figure on the right.

3.Hold the projected part of the rear cover with one hand, hold the front cover with the other hand, and then lift and remove the rear cover upwards.

	Caution : If you remove the rear
	cover by holding and lifting
Rear Cover	the red circle part marked
	with ‘NO’ upwards (to the
	left of the figure on the	NO			YES
	right), a crack may occur
	on the Function-PCB
	connector. Make sure to
	hold and lift the red circle
	part marked with ‘YES’
	upwards (to the right of the
	right figure) to remove the
						If handled
	rear cover.
						incorrectly,
						a crack may
						occur on the
						Function-PCB
						connector.

3-3

3. Disassembly and Reassemble

Part

Description

Picture Description

Screws

4. Remove the shield lamp using a flat

SHIELD- screwdriver or the provided jig.

LAMP Caution : Be careful because the shield lamp is sharp.

	Removing	5. Remove the lamp wire, function wire,
		speaker connector, and LVDS cable
	the cables
		connected to the chassis.

	ASSY	6. Remove the four (4) hex screws on
		the bottom of the shield, as shown in
	CHASSIS
		the right figure.

7. Remove the eight (8) screws designated in the right figure, lift the boards upward and remove the cable shown in the figure on the right.

MAIN

BOARD,

IP-Board

8.Remove the main board and IP-board from the shield cover.

Reassembly procedures are in the reverse order of disassembly procedures.

3-4

4. Troubleshooting

4. Troubleshooting

4-1. Troubleshooting

1.Before troubleshooting, setup the PC ‘s display as below.

•Resolution: 1920 x 1080

•H-frequency: 75 kHz

•V-frequency: 60 Hz

2.If no picture appears, make sure the power cord is correctly connected.

3.Check the following circuits.

•No raster appears: Function PBA. Main PBA. IP-Board

•5V develop but no screen : Main PBA

•13V, 5V does not develop: IP-Board, Main PBA

4-1

4. Troubleshooting

4-2. When the Power Does Not Turn On

	Symptom	- 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.

Major checkpoints - 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.

CN600

IC203

Diagnostics			Main Board Front
		Check the connection status of the
		Function assy.
		Can DC 5V be measured on pins 6, 7		No
		of the CN600 connector when pins 3, 4,				Replace the IP board.
		and 5 are 0V?
			Yes
		Can DC 3.3V be measured on pin 3 of		No		Check the circuits related to
						the IC203.
		the IC203 when pin 1 is DC 5V?
			Yes
		Check and replace the main board
		related to the scaler.
Caution	Make sure to disconnect the power before working on the IP board.

4-2

4. Troubleshooting

4-2-1. Circuit Diagram and Waveform for Power Failures

4-3