SAMSUNG CKB5237L Service Manual

COLOR MONITOR

CKB5237L

CKB7227L

SERVICEManual

COLOR MONITOR

– +

MENU

EXIT

1.Precautions

2.Product Specifications

3.Operating Instructions

4.Disassembly & Reassembly

5.Alignment & Adjustments

6.Troubleshooting

7.Exploded View & Parts

8.Block Diagram

9.Wiring Diagram

10.PCB Diagrams &

11.Schematic Diagrams

Samsung Electronics Co., Ltd. October 1997

Printed in Korea

Code No.: BH68-60934A

1 Precautions

Follow these safety, servicing and ESD precautions to prevent damage and to protect against potential hazards such as electrical shock and X-rays.

1-1 Safety Precautions

1-1-1 Warnings

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

2.Disconnect the AC power before servicing.

3.When the chassis is operating, semiconductor heatsinks are potential shock hazards.

1-1-2 Servicing the High Voltage System and

CRT

WARNING: A high voltage VR replaced in the wrong direction may cause excessive X-ray emissions.

Caution: When replacing the high voltage adjustment VR, it must be fixed by a soldering iron after it is properly set.

1.When servicing the high voltage system, remove the static charge by connecting a 10k ohm resistor in series with an insulated wire (such as a test probe) between the chassis and the anode lead. (Disconnect the AC line cord from the AC outlet.)

2.High Voltage VR Replacement

If the high voltage system requires adjustment, use the following procedure (all steps are required):

a.Turn the power off and disconnect the AC line cord from the power source.

b.Unsolder and remove the high voltage VR on the Main PCB.

c.Replace the VR and adjust the high voltage to the specification.

d.Using a soldering iron, melt the adjustment cap on the high voltage VR to prevent any movement.

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

4.When troubleshooting a monitor with excessively high voltage, avoid being unnecessarily close to the monitor. Do not operate the monitor for longer than is necessary to locate the cause of excessive voltage.

5.High voltage should always be kept at the rated value, no higher. Be sure all service personnel are aware of the procedures and instructions covering X-rays.

The only potential source of X-ray in current solid state display monitors is the tube. However, the CRT does not emit measurable X-ray radiation if the high voltage is at the high voltage adjustment value.

Only when high voltage is excessive are X-rays capable of penetrating the shell of the CRT, including the lead in glass material. Operation at high voltages may also cause failure of the CRT or high voltage circuitry.

6.When the high voltage regulator is operating properly, there is no possibility of an X-ray problem. Test the brightness and use a meter to monitor the high voltage each time a color monitor comes in for service. Make sure the high voltage does not exceed its specified value and that it is regulating correctly.

7.The CRT is especially designed to prohibit X-ray emissions. To ensure continued X-ray protection, replace the CRT with only one that is the same or equivalent type as the original. Carefully reinstall the CRT shields and mounting hardware; these also provide X-ray protection.

8.Handle the CRT only when wearing shatterproof goggles and after completely discharging the high voltage anode.

9.Do not lift the CRT by the neck.

CKB5237L/7227L

1-1

1 Precautions

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 resistor-capacitor networks, mechanical insulators, etc.

	(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

Figure1-1. Leakage Current Test Circuit

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).

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 safety-related 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.

Components identified by on schematics and parts lists must be sealed by a soldering iron after replacement and adjustment.

1-2	CKB5237L/7227L

1 Precautions

1-2 Servicing Precautions

WARNINGS: A high voltage VR replaced in the wrong direction may cause excessive X-ray emissions.

An electrolytic capacitor installed with the wrong polarity might explode.

Cautions: Before servicing instruments covered by this service bulletin, read and follow the Safety Precautions section of this manual.

When replacing the high voltage adjustment VR, it must be fixed by a soldering iron after it is properly set.

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.Servicing precautions are printed on the cabinet, and should be followed closely.

2.Always unplug the unit’s AC power cord from the AC power source 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.

3.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.

4.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.

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

6.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 the blades 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.

7.Never defeat any of the +B voltage interlocks. Do not apply AC power to the unit (or any of its assemblies) unless all solid-state heat sinks are correctly installed.

8.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.

CKB5237L/7227L

1-3

1 Precautions

1-3 Electrostatically Sensitive Devices (ESD) 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 devices 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.

9. Indicates ESDs on the Schematic Diagram in this manual.

1-4	CKB5237L/7227L

2 Product Specifications

2-1 Specifications

Item				Description
Picture Tube:	17-Inch (43 cm): 15.7-inch (39.80 cm) viewable; 15-Inch (38 cm): 13.8-inch (35 cm) viewable;
	Full-square flat-face tube, 90˚ Deflection, 0.28 mm Dot pitch, Semitint, Non-glare, Invar
	shadow mask, Anti-static silica coating
Scanning Frequency	Horizontal : 30 kHz to 70 kHz (Automatic)
	Vertical	: 50 Hz to 120 Hz (Automatic)
Display Colors	Unlimited colors
Maximum Resolution	Horizontal : 1280 Dots
	Vertical	: 1024 Lines
Input Video Signal	Analog, 0.714 Vp-p positive at 75 Ω , internally terminated
Input Sync Signal	Separate Sync : TTL level positive/negative
Maximum Pixel Clock rate	110 MHz
Active Display	CKB5237L ; Horizontal : 267 mm ± 3 mm, Vertical : 200 mm ± 3 mm
	CKB7227L ; Horizontal : 306 mm ± 3 mm (4:3 ratio), Vertical : 230 mm ± 3 mm
Input Voltage	AC 90 to 264 Volts, 60 Hz or 50 Hz ± 3 Hz
Power Consumption	90 Watt (max) : 17”, 85 Watt (max) : 15”
Dimensions		CKB5237L				CKB7227L
Unit (W x D x H)	14.6 x 15.6 x 15.5 Inches (370 x 397 x 394 mm),					16.8 x 17.0 x 17.1 Inches (426 x 433 x 434 mm)
Carton (W x D x H)	18.2 x 21.0 x 17.7 Inches (462 x 534 x 450 mm)					21.3 x 21.8 x 21.2 Inches (541 x 554 x 538 mm)
Weight	CKB5237L : 30 lbs (13.6 kg) / 35.3 lbs (16.0 kg)
(Net/Gross)	CKB7227L : 40.8 lbs (18.5 kg) / 46.7 lbs (21.2 kg)
Environmental Considerations	Operating Temperature		:	32°F to 104°F (0°C to 40°C)
	Humidity : 10 % to 80 %
	Storage Temperature		:	-4°F to 113°F (-20°C to 45°C)
	Humidity : 5 % to 95 %
CRT Code No.	BH03-10337T : M41KUN36X03(E/L/LP), Silica Coating - 17”
	BH03-10337U : M41KUN36X03(A/L/LP), Multi Coating - 17”
	BH03-10337V : M41KUN36X03(T4/L/LP), Multi Coating (TCO) - 17”
	BH03-10337W : M41KUK35X02(E/LP), ESF - 15”
	BH03-10337X : M36KUK35X02(T4/LP), Multi Coating (TCO) - 15”

•Above models comply with SWEDAC (MPR II) recommendations for reduced electromagnetic fields.

•Designs and specifications are subject to change without prior notice.

CKB5237L/7227L

2-1

2 Product Specifications

2-2 Pin Assignments

	Sync	15-Pin Signal Cable Connector (Figure 2-5)	Cable Adapter (Figure 2-6)
	Type		Macintosh
		Separate
	Pin No.
	1	Red	GND-R
	2	Green	Red
	3	Blue	H/V Sync
	4	GND	Sense 0
	5	DDC Return	Green
	6	GND-R	GND-G
	7	GND-G	Sense 1
	8	GND-B	Reserved
	9	Reserved	Blue
	10	GND-Sync/Self-raster	Sense 2
	11	GND	GND
	12	DDC Data	V-Sync
	13	H-Sync	GND-B
	14	V-Sync	GND
	15	DDC Clock	H-Sync

5

15

Figure 2-5. Male Type Figure 2-6. Male Type

2-2	CKB5237L/7227L

2 Product Specifications

2-3 Timing Chart

This section of the service manual describes the timing that the computer industry recognizes as standard for computer-generated video signals.

Table 2-1. Timing Chart

Mode		IBM		VESA
	VGA2/70 Hz	VGA3/60 Hz	640/75 Hz	640/85 Hz	800/75 Hz
Timing	720 x 400	640 x 480	640 x 480	640 x 480	800 x 600
fH (kHz)	31.469	31.469	37.500	43.269	46.875
A µsec	31.778	31.778	26.667	23.111	21.333
B µsec	3.813	3.813	2.032	1.556	1.616
C µsec	1.907	1.907	3.810	2.222	3.232
D µsec	25.422	25.422	20.317	17.778	16.162
E µsec	0.636	0.636	0.508	1.556	0.323
fv (Hz)	70.087	59.940	75.000	85.008	75.000
O msec	14.268	16.683	13.333	11.764	13.333
P msec	0.064	0.064	0.080	0.671	0.064
Q msec	1.080	1.048	0.427	0.578	0.448
R msec	12.711	15.253	12.800	11.093	12.800
S msec	0.413	0.318	0.027	0.023	0.021
Clock
Frequency	28.322	25.175	31.500	36.000	49.500
(MHz)
Polarity
H.Sync	Negative	Negative	Negative	Negative	Positive
V.Sync	Positive	Negative	Negative	Negative	Positive
Remark	Separate	Separate	Separate	Separate	Separate

		Separate Sync
Horizontal			Vertical
Video			Video
C C	DD	E E	Q Q		R R	S S
Sync			Sync
	B			P	P
	B
	A A				O O

A : Line time total	B : Horizontal sync width	O : Frame time total	P : Vertical sync width
C : Back porch	D : Active time	Q : Back porch	R : Active time
E : Front porch		S : Front porch

CKB5237L/7227L

2-3

2 Product Specifications

Table 2-1. Timing Chart Continued

Mode		VESA
	800/85Hz	1024/75 Hz	1024/85 Hz
Timing	800 x 600	1024 x 768	1024 x 768
fH (kHz)	53.674	60.023	68.677
A µsec	18.631	16.660	14.561
B µsec	1.138	1.219	1.016
C µsec	2.702	2.235	2.201
D µsec	14.222	13.003	10.836
E µsec	0.569	0.203	0.508
fv (Hz)	85.061	75.029	84.997
O msec	11.756	13.328	11.765
P msec	0.056	0.050	0.044
Q msec	0.503	0.466	0.524
R msec	11.179	12.795	11.183
S msec	0.019	0.017	0.015
Clock
Frequency	56.250	78.750	94.500
(MHz)
Polarity
H.Sync	Positive	Positive	Positive
V.Sync	Positive	Positive	Positive
Remark	Separate	Separate	Separate

Separate Sync

Horizontal

Vertical

Video

Video

C C

DD

E E

Q Q

RR

S S

Sync

Sync

B

PP

	A A				O O

A : Line time total	B : Horizontal sync width	O : Frame time total	P : Vertical sync width
C : Back porch	D : Active time	Q : Back porch	R : Active time
E : Front porch		S : Front porch

2-4	CKB5237L/7227L

3 Opearating Instructions

3-1 Front View and Control

3-1-1 CKB5237L/7227L Front View

– +

MENU

EXIT

			1	7	8	9
			2
				Figure 3-2. Rear View
				Table 3-1. Front Panel Controls
			Location	Symbol		Description
	–	+	1			Power Button
MENU
EXIT
			2			Power Indicator LED (Dual Color)
			3	MENU		Menu Display & Menu Exit
				EXIT
			4	–		Down Button & Brightness
3	4	5	6	+
			5			Up Button & Contrast
Figure 3-1. Front Control Panel
			6			Menu Selector Enter Key
			7			3 Pin AC Power Input
			8			USB Jack Input (Optional)
			9			Signal Input

CKB5237L/7227L

3-1

3 Operating Instructions

3-2-1 On Screen Display

This monitor features an On-Screen Display (OSD) that shows information about the display setting. The OSD appears on the screen when you select a function button. The OSD can show the name, range and current setting of the control function. In addition, the OSD shows the current input signal frequency and the list of user and factory preset timings. The OSD remains active for approximately 5 seconds after the completion of any adjustment.

3-2-2 OSD Window

Push the menu button to open the OSD. The Main Menu shows all of the adjustment icons along the top of the window. The window shows one or more adjustment names in the Adjustment Box and instructions display in the Information Bar.

MENU

?

BRIGHTNESS

To access a function, use the menu button to move to its associated icon, and then use the – or

+ button to select the adjustment type. Then, push the button to access the function.

All OSD windows change color to indicate that the associated adjustment control is active. When the OSD displays the name of the adjustment, for example, Pincushion/Trap, with a green border, adjustments for pincushion or trapezoidal effects are available. Each OSD window shows directions for use along the bottom of the window. When you are satisfied with the adjustments you have made to the current control, select the Exit button to return to the OSD Menu where you can select another control, or exit from the OSD system and save your changes. The OSD remains active for approximately 10 seconds after completion of any adjustments.

3-2-4 Direct Controls

The on-screen Direct controls have the following two functions:

•Brightness: With the menu off, push the				–
button. The brightness display will
appear.
Push the	+	button to increase the
brightness or the			– button to
decrease the brightness.
•Contrast: With the menu off, push the				+
button. The contrast adjustment
display will appear.
Push the	+	button to increase the
contrast or the			– button to
decrease the contrast.

3-2	CKB5237L/7227L

3 Operating Instructions

Note 1: This monitor requires a cable adapter for use with a Macintosh computer. The MacMaster Cable Adapter supports all monitors and all Macintosh, Centris, Quadra, Duo Dock, and Power Macintosh computers. If you do not already have a cable adapter, check with your computer dealer.

Note 2: When used with a computer equipped with VESA DPMS functions, this monitor is EPA Energy Star compliant and NUTEK compliant.

Table 3-2. Display Power Management Signaling (DPMS)

;CKB7227L

	State	Normal	Power saving function EPA/NUTEK
	Items	Operation	Stand-By	Suspend Mode	Power Off Mode
			Mode	Position A	Position B
	Horizontal Sync	Active	Inactive	Active	Inactive
	Vertical Sync	Active	Active	Inactive	Inactive
	Video	Active	Blanked	Blanked	Blanked
	Power	Green	Amber	Alternating	Amber
				Amber/Green
	Indicator				Blinking
				Blinking
	Power	90 W (max.)	72 W (max.)	Less than	Less than
		78 W	65 W
	Consumption/hr			15 W	8 W
		(nominal)	(nominal)

Table 3-3. Display Power Management Signaling (DPMS)

;CKB5237L

	State	Normal	Power saving function EPA/NUTEK
	Items	Operation	Stand-By	Suspend Mode	Power Off Mode
			Mode	Position A	Position B
	Horizontal Sync	Active	Inactive	Active	Inactive
	Vertical Sync	Active	Active	Inactive	Inactive
	Video	Active	Blanked	Blanked	Blanked
	Power	Green	Amber	Alternating	Amber
				Amber/Green
	Indicator				Blinking
				Blinking
	Power	85 W (max.)	72 W (max.)	Less than	Less than
		70 W	65 W
	Consumption/hr			15 W	8 W
		(nominal)	(nominal)

CKB5237L/7227L

3-3

3 Operating Instructions

Memo

3-4	CKB5237L/7227L

4 Disassembly and Reassembly

This section of the service manual describes the disassembly and reassembly procedures for the CKB5237L/7227L monitors.

WARNING: This monitor contains electrostatically sensitive devices. Use caution when handling these components.

4-1 Disassembly (CKB7227L)

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.

4-1-1 Cabinet Disassembly

1.With a pad beneath it, stand the monitor on its front with the screen facing downward and the base close to you. Make sure nothing will damage the screen.

2.Working from the back of the monitor remove the signal cover cap out, and remove the 4 screws and carefully pull the rear cabinet up and off the monitor.

3.Remove the 8 screws on the Top Shield and remove it.

4.Remove the 4 screws on the Bottom Cover and pull it upward to remove it.

5.Using pinch-nosed pliers or long-nosed pliers, carefully disconnect the Anode Cap from the CRT.

4-1-2 Removing the Video PCB &

CRT Socket PCB

1.Follow steps 1 through 5 in “Cabinet Disassembly,” above.

2.Disconnect connectors CN103.

3.Lift off the CRT Socket PCB Assembly.

4.Hold the CRT Socket PCB Assembly while you lift the cap on the CRT Socket and pull out the two focus wires, G2 wire.

5.Remove both side screws on the lower edge of the Video PCB Ass’y and the screw on the signal connector and pull the assembly towards you to remove it.

6.Remove all screws on the Video PCB Assembly and remove the Video Shield.

7.Lift out the Video PCB and place it on a flat, level surface that is protected from static electricity.

4-1-3 Removing the Main PCB

1.Follow steps 1 through 5 in “Cabinet Disassembly,” steps 1 through 7 in “Removing the Video PCB and “Removing the CRT Socket PCB,” above.

2.Disconnect the Degaussing Coil at CN600 on the Main PCB.

3.Disconnect all easily accessible ground wires from the CRT GND Assembly and Bottom Chassis.

4.Disconnect the connector between CN_Tilt. on the Main PCB and the Tilt coil.

5.Disconnect the DY connector between the DY and the CN300A_7, CN400, CN401 and CN402 connectors on the Main PCB.

6.Remove the 2 screws on the left and right sides of the PCB Bracket.

7.Carefully lift the Main PCB Ass’y.

8.Remove the 7 screws on the top side of the Main PCB.

9.Lift the Main PCB and place it on a flat, level surface that is protected from static electricity.

CKB5237L/7227L

4-1

4 Disassembly and Reassembly

4-1-4 CRT Ass’y Disassembly

1.Complete all previous steps.

2.Remove the 4 side screws 2 on the top and 2 on either side of the CRT and lift the CRT Unit Bracket.

3.Unhook the Degaussing Coil Assembly and lift it off the CRT.

4.Remove the 4 corner screws and lift the CRT up and away from the Front Cover Assembly and place it on a padded surface.

!Do not lift the CRT by the neck.

Caution: If you will be returning this CRT to the monitor, be sure to place the CRT face down on a protective pad.

4-2 Reassembly (CKB7227L)

With the CRT facing downward on a protective pad, use the steps that follow to reassemble the monitor.

4-2-1 Replacing the CRT

1.Loop the CRT Ground Assembly around the back of the CRT and under the 3 corner, metal ears. Position the corner with the spring last.

2.With the Front Cover Assembly lying face down on a protective pad, position the CRT so that the corner metal ears fit properly in the Front Cover Assembly.

3.Replace the 4 corner screws.

4.Replace the Degaussing Coil Assembly and secure the Coil with the plastic Degaussing Coil Holders.

5.Replace the CRT Ground Assembly.

6.Replace the Unit Bracket Assembly.

4-2-2 Replacing the Main PCB

1.Stand the monitor on its front with the screen facing downward.

2.Replace the 7 screws on the top side of the Main PCB.

3.Position the Main PCB Ass’y in the Front Cabinet and secure it on both sides with the screws between the Bottom Chassis and CRT Unit Bracket.

4.Replace the DY connector at the CN300A_7, CN400, CN401 and CN402 connectors on the Main PCB.

5.Replace the connector between CN_Tilt. on the Main PCB and the Tilt Coil.

6.Replace all easily accessible ground wires on the CRT GND Assembly and Bottom Chassis.

7.Replace the Degaussing Coil at CN600 on the Main PCB.

8.Replace the Anode Cap.

4-2-3 Replacing Connector CN103 on the Video PCB

1.Position the Video Shield and replace all screws.

2.Replace both side screws on the lower edge of the Video PCB Ass’y and the screw on the signal connector.

4-2-4 Replacing the CRT Socket PCB

1.Hold the CRT Socket PCB Ass’y while you lift the Cap on the CRT Socket and replace the two Focus wires, G2 wire.

2.Reconnect the CRT Socket on the CRT pins at the plug/Socket junction.

4-2-5 Cabinet Reassembly

1.Reconnect CN103 on the Video PCB.

2.Position the Top Shield and replace the 8 screws.

3.Replace the 4 screws on the Bottom Cover.

4.Position the Rear Cover making sure that the tabs along the front edge are properly snapped in place. Replace the 4 screws.

5.Replace the signal cable cover cap.

6.Set the monitor on its Base and make sure that the CRT faceplate was not scratched or otherwise damaged.

4-2	CKB5237L/7227L

4 Disassembly and Reassembly

4-3 Disassembly (CKB5237L)

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.

4-3-1 Cabinet Disassembly

1.With a pad beneath it, stand the monitor on its front with the screen facing downward and the base close to you. Make sure nothing will damage the screen.

2.Working from the back of the monitor remove the signal cover cap out, and remove the 4 screws and carefully pull the rear cabinet up and off the monitor.

3.Using pinch-nosed pliers or long-nosed pliers, carefully disconnect the Anode Cap from the CRT.

4-3-2 Removing the Video PCB &

CRT Socket PCB

1.Follow steps 1 through 3 in “Cabinet Disassembly,” above.

2.Remove the 1 screw on the Video Shield Top position.

3.Disconnect connector C103.

4.Lift off the CRT Socket PCB Assembly.

5.Hold the CRT Socket PCB Assembly while you lift the cap on the CRT Socket, unsolde 1 point wire, remove 9 pin wire Assembly, unsolder 4 point on the corner shild of CRT Socket PCB and remove shield of CRT Socket PCB.

6.Remove 5 point screws side the lower edge and back of the Video PCB Assembly, and the screw on the signal conector and pull the Assembly towards you to remove it.

7.Remove all screws on the Video PCB Assembly and remove the Video Shield.

8.Lift out the Video PCB and place it on a flat, level surface that is protected from static electricity.

4-3-3 Removing the Main PCB

1.Follow steps 1 through 3 in “Cabinet Disassembly,” steps 1 through 8 in “Removing the Video PCB and “Removing the CRT Socket PCB,” above.

2.Disconnect the Degaussing Coil at CN600 on the Main PCB.

3.Disconnect all easily accessible ground wires from the CRT GND Assembly and Bottom Chassis.

4.Disconnect the connector between CN_Tilt. on the Main PCB and the Tilt coil.

5.Disconnect the DY connector between the DY and the CN301_5, CN400, CN401 and CN402 connectors on the Main PCB.

6.Remove the 2 screws on the left and right sides of the PCB Bracket.

7.Carefully lift the Main PCB Ass’y.

8.Remove the 7 screws on the top side of the Main PCB.

9.Lift the Main PCB and place it on a flat, level surface that is protected from static electricity.

CKB5237L/7227L

4-3

4 Disassembly and Reassembly

4-4 Reassembly (CKB5237L)

With the CRT facing downward on a protective pad, use the steps that follow to reassemble the monitor.

4-4-1 Replacing the CRT

1.Loop the CRT Ground Assembly around the back of the CRT and under the 4 corner, metal ears. Position the corner with the spring last.

2.With the Front Cover Assembly lying face down on a protective pad, position the CRT so that the corner metal ears fit properly in the Front Cover Assembly.

3.Replace the 4 corner screws.

4.Replace the Degaussing Coil Assembly and wrap the coil with the plastic coated matal ties to hold the coil in place.

5.Replace the CRT Ground Assembly.

6.Replace the Unit Bracket Assembly.

4-4-2 Replacing the Main PCB

1.Stand the monitor on its front with the screen facing downward.

7.Replace the Degaussing Coil at CN600 on the Main PCB.

8.Replace the Anode Cap.

4-4-3 Replacing Connector CN103 on the Video PCB

1.Position the Video Shield and replace all screws.

2.Replace 4 point both and back screws on the lower edge of the Video PCB Ass’y and the screw on the signal connector.

4-4-4 Replacing the CRT Socket PCB

1.Hold the CRT Socket PCB Ass’y while you lift the Cap on the CRT Socket and replace the Focus wire, G2 wire.

2.Reconnect the CRT Socket on the CRT pins at the plug/Socket junction.

2.Replace the 7 screws on the top side of the Main PCB.

3.Position the Main PCB Ass’y in the Front Cabinet and secure it on both sides with the screws between the Bottom Chassis and CRT Unit Bracket.

4.Replace the DY connector at the CN301_5, CN400, CN401 and CN402 connectors on the Main PCB.

5.Replace the connector between CN_Tilt. on the Main PCB and the Tilt Coil.

6.Replace all easily accessible ground wires on the CRT GND Assembly and Bottom Chassis.

4-4-5 Cabinet Reassembly

1.Reconnection CN103 both the CRT and the Video PCB.

2.Solder 1 point CRT PCB and replace 1 screw Video shield.

3.Replace the 4 screws on the Bottom Cover.

4.Position the Rear Cover making sure that the tabs along the front edge are properly snapped in place. Replace the 4 screws.

5.Replace the signal cable cover cap.

6.Set the monitor on its Base and make sure that the CRT faceplate was not scratched or otherwise damaged.

4-4	CKB5237L/7227L

5 Alignment and Adjustments

This section of the service manual explains how to make permanent adjustments to the monitor. Directions are given for adjustments using the monitor Interface Board Ver. 2.0 and software (SoftJig).

5-1 Adjustment Conditions

Caution: Changes made without the SoftJig are saved only to the user mode settings. As such, the settings are not permanently stored and may be inadvertently deleted by the user.

5-1-1 Before Making Adjustments

5-1-1 (a) ORIENTATION

When servicing, always face the monitor to the east.

5-1-1 (b) MAGNETIC FIELDS

Whenever possible, use magnetic field isolation equipment such as a Helmholtz field to surround the monitor. If a Helmholtz field is not available, frequently degauss the unit under test.

Caution: Other electrical equipment may cause external magnetic fields which may interfere with monitor performance.

Use an external degaussing coil to limit magnetic build up on the monitor. If an external degaussing coil is not available, use the internal degaussing circuit. However, do not use the internal degaussing circuit more than once per 30 minutes.

5-1-1 (c) WARM-UP TIME

5-1-1 (f) HIGH VOLTAGE ADJUSTMENT

Signal:	No signal
Display image:	Self raster
Contrast:	Maximum
Brightness:	Maximum
Limit:	26 kV ± 0.2 kV (17”)
	25 kV ± 0.2 kV (15”)

Measure the hight voltage level at the anode cap. High voltage should be within the limit as above. If the high voltage needs adjustment use the following procedure.

PROCEDURE

1.Turn the power off and disconnect the AC line cord from the power source.

2.Unsolder and remove VR501 on the Main PCB.

3.Replace VR501 and adjust the high voltage to the specification.

4.Using a soldering iron, melt the adjustment cap on VR501 to prevent any movement.

The monitor must be on for 30 minutes before starting alignment. Warm-up time is especially critical in color temperature and white balance adjustments.

5-1-1 (d) SIGNAL

Analog, 0.714 Vp-p positive at 75 ohm, internal termination

Sync: Separate

(TTL level negative/positive)

5-1-1 (e) SCANNING FREQUENCY

Horizontal:	30 kHz to 70 kHz (Automatic)
Vertical:	50 Hz to 120 Hz (Automatic)

Unless otherwise specified, adjust at the

17”: 1024 x 768 mode (68 kHz/85 Hz), 15”: 800 x 600 mode (54 kHz/85 Hz) signals.

Refer to Table 2-1 on pages 2-4 and 2-5.

5-1-1 (g) G2 (SCREEN) VOLTAGE ADJUSTMENT (17” ONLY)

Signal:	No signal
Display image:	Self raster
Contrast:	Maximum
Brightness:	Maximum

Adjust the Screen VR of the FBT so that the G2 (Screen) Voltage for SDD CRT is 450 V ± 10 V.

5-1-1 (h) CENTER RASTER

Adjust SW401 so that the back raster comes to the center when you apply a signal of 60 kHz/75 Hz.

CKB5237L/7227L

5-1

5 Alignment and Adjustments

5-1-2 Required Equipment

The following equipment may be necessary for adjustment procedures:

5-1-2 (a) DISPLAY CONTROL ADJUSTMENT

1.Non-metallic (–) screwdriver: 1.5 mm Non-metallic (–) screwdriver: 3 mm

2.Philips (+) screwdriver: 1.5 mm

3.Non-metallic hexkey: 2.5 mm

4.Digital Multimeter (DMM), or Digital Voltmeter (DVM)

5.Signal generator, or

Computer with a video board that uses the ET-4000 chipset (strongly recommended if using Samsung DM 200 software) and that displays: 1024 x 768 @ 85 Hz, or 800 x 600 @ 85 Hz (minimum).

6.Personal computer

7.Required software: Softjig.exe from Samsung which includes the cg17e.c data file Samsung DM200, or DisplayMate for Windows from Sonera Technologies

8.Interface Board Ver. 2.0 Code No. BH81-90001K

9.Parallel communications cable (25-pin to 25-pin); Code No. BH81-90001H

10.Signal cable (15-pin to 15-pin cable with additional 3-pin connector); Code No. BH81-90001J

11.5 V DC adapter, not supplied

Note: SoftJig Ass’y (includes items 8, 9 and 10) Code No. BH81-90001L

5.1-2 (b) COLOR ADJUSTMENTS

1.All equipment listed in 5-1-2 (a), above

2.Color analyzer, or any luminance measurement equipment

5-1-3 Connecting the SoftJig

Connect the monitor to the signal generator and/ or PC as illustrated in Figures 5-1 and 5-2.

Note: The signal cable connector which includes the 3-wire cable must connect to the monitor. If you use Setup 2 (PC only, no signal generator) you can only make adjustments to the signal timing available on that computer system. To make corrections to all factory timings requires the use of an additional signal generator.

	MONITOR
INTERFACE
BOARD VER. 2.0	SIGNAL CABLE

5V DC

ADAPTOR 3-WIRE CABLE

PARALLEL CABLE

	PC	SIGNAL
		GENERATOR

Figure 5-1 : Setup 1, With Signal Generator

	MONITOR
INTERFACE
BOARD VER. 2.0	3-WIRE CABLE
5V DC
ADAPTOR
	SIGNAL CABLE
PARALLEL CABLE	D-SUB
PC	CONNECTOR

Figure 5-2. Setup 2, Without Signal Generator

5-1-4 After Making Adjustments

After finishing all adjustments, test the monitor in all directions. If, for example, the monitor does not meet adjustment specifications when facing north, reposition the monitor to face east and readjust.

This time, try for an adjustment closer to the ideal setting within the tolerance range. Test the unit again in all directions. If the monitor again fails to meet specifications in every direction, contact your Regional After Service Center for possible CRT replacement.

5-2	CKB5237L/7227L

5 Alignment and Adjustments

5-2 Display Control Adjustments

5-2-1 Centering

Centering means to position the center point of the display in the middle of the display area. Horizontal size and position and vertical size and position control the centering of the display.

Adjust the horizontal size and vertical size to their optimal settings: 306 mm (H) x 230 mm (V) for 17”, 267 mm (H) x 200 mm (V) for 15”.

Adjust the horizontal position and vertical position to ≤ 4.0 mm of the center point of the screen.

|A-B| ≤ 4.0 mm.
|C-D| ≤ 4.0 mm. C
	DISPLAY AREA
A	B
	EDGE OF BEZEL
D

Figure 5-3. Centering

5-2-1 (a) HORIZONTAL SIZE ADJUSTMENT

CONDITIONS
Scanning frequency:	68 kHz/85 Hz (17”)
	54 kHz/85 Hz (15”)
Display image:	Crosshatch pattern
Brightness:	Maximum
Contrast:	Maximum

Click on the << or >> box next to B+OUT to adjust the horizontal size of the display pattern to 306 mm (17”) and 267 mm (15”).

(Tolerance: ± 3 mm.)

5-2-1 (b) VERTICAL SIZE ADJUSTMENT

CONDITIONS
Scanning frequency:	68 kHz/85 Hz (17”)
	54 kHz/85 Hz (15”)
Display image:	Crosshatch pattern
Brightness:	Maximum
Contrast:	Maximum

Click on the << or >> box next to V_SIZE to adjust the vertical size of the display pattern to 230 mm (17”) and 200 mm (15”).

(Tolerance: ± 3 mm.)

5-2-1 (c) HORIZONTAL POSITION ADJUSTMENT

CONDITIONS
Scanning frequency:	68 kHz/85 Hz (17”)
	54 kHz/85 Hz (15”)
Display image:	Crosshatch pattern

Click on the << or >> box next to H_POSI to center the horizontal image on the raster.

5-3-1 (d) VERTICAL POSITION ADJUSTMENT

CONDITIONS
Scanning frequency:	68 kHz/85 Hz (17”)
	54 kHz/85 Hz (15”)
Display image:	Crosshatch pattern

Click on the << or >> box next to V_POSI to center the vertical image on the raster.

5-2-2 Linearity

Linearity affects the symmetry of images as they appear on the screen. Unless each row or column of blocks in a crosshatch pattern is of equal size, or within the tolerances shown in Tables 5-2 and 5-3, an image appears distorted, elongated or squashed.

Table 5-1. Standard Modes Linearity: 640x480/75Hz, 800x600/85Hz and 1024x768/85Hz

			Standard Modes Linearity
		Each block (10 %)		Difference between
				adjacent blocks (4 %)
	4 : 3	Horizontal: 18.2~20.1		Horizontal: Less than 0.77 mm
		Vertical	: 18.2~20.1	Vertical	: Less than 0.77 mm
	5 : 4	Horizontal: 17.1~18.9		Horizontal: Less than 0.72 mm
		Vertical	: 18.2~20.1	Vertical	: Less than 0.77 mm

Table 5-2. Other Modes Linearity: VGA, SVGA, XGA,

MAC, etc.

			Supported Timing Mode
		Each block (14 %)		Difference between
				adjacent blocks (5 %)
	4 : 3	Horizontal: 17.8~20.5		Horizontal: Less than 0.96 mm
		Vertical	: 17.8~20.5	Vertical	: Less than 0.96 mm
	5 : 4	Horizontal: 16.7~19.2		Horizontal: Less than 0.90 mm
		Vertical	: 17.8~20.5	Vertical	: Less than 0.96 mm

CKB5237L/7227L

5-3

5 Alignment and Adjustments

5-2-2 (a) HORIZONTAL LINEARITY ADJUSTMENT

The CKB5237L/7227L monitors offer only Vertical Linearity adjustments. Horizontal Linearity is fixed on the Chassis and is not adjustable.

5-2-2 (b) VERTICAL LINEARITY ADJUSTMENT

CONDITIONS
Scanning frequency:	68 kHz/85 Hz (17”)
	54 kHz/85 Hz (15”)
Display image:	Crosshatch pattern
Brightness:	Maximum
Contrast:	Maximum

To adjust the Vertical Linearity, refer to Tables 5-2 and 5-3 for the tolerance range.

Click on the << or >> box next to V_LIN to optimize the image.

5-2-3 Trapezoid Adjustment

CONDITIONS
Scanning frequency:	68 kHz/85 Hz (17”)
	54 kHz/85 Hz (15”)
Display image:	Crosshatch pattern
Brightness:	Maximum
Contrast:	Maximum

Click on the << or >> box next to TRAPE to make the image area rectangular.

| A - B | < 4 mm

A

A

B

B

Figure 5-4. Trapezoid

5-2-4 Pinbalance Adjustment

CONDITIONS
Scanning frequency:	68 kHz/85 Hz (17”)
	54 kHz/85 Hz (15”)
Display image:	Crosshatch pattern
Brightness:	Maximum
Contrast:	Maximum

D1

D2

D1

Figure 5-5. Pinbalance

Click on the << or >> box next to PIN_BAL to optimize the image.

5-2-5 Parallelogram Adjustment

CONDITIONS
Scanning Frequency:	68 kHz/85 Hz (17”)
	54 kHz/85 Hz (15”)
Display image:	Crosshatch pattern
Brightness:	Maximum
Contrast:	Maximum

Click on the << or >> box next to PARALL to make the image area rectangular.

4 mm

Figure 5-6. Parallelogram

5-4	CKB5237L/7227L

5-2-6 Side Pincushion Adjustment

CONDITIONS
Scanning frequency:	68 kHz/85 Hz (17”)
	54 kHz/85 Hz (15”)
Display image:	Crosshatch pattern

Click on the << or >> box next to BARREL to straighten the sides of the image area.

| C1 |, | C2 | ≤ 2.0 mm, | D1 |, | D2 | ≤ 2.0 mm.

C2

D1

D2

C1

Figure 5-7. Pincushion

	5 Alignment and Adjustments
5-2-7 Tilt Adjustment
CONDITIONS
Scanning Frequency:	68 kHz/85 Hz (17”)
	54 kHz/85 Hz (15”)
Display image:	Crosshatch pattern
Brightness:	Maximum
Contrast:	Maximum

Click on the << or >> box next to ROTATE to correct the tilt of the display.

5-2-8 Degauss

No adjustments are available for the degaussing circuit. The degaussing circuit can effectively function only once per 30 minutes.

5-2-9 To Delete the User Mode Data

To delete the adjustment data from the user modes, click USER DELETE.

5-2-10 Save the Data

To save the adjustment data for a mode, press

FACTORY SAVE.

CKB5237L/7227L

5-5

5 Alignment and Adjustments

5-3 Color Adjustments

5-3-1 Color Coordinates (Temperature)

Color temperature is a measurement of the radiant energy transmitted by a color. For computer monitors, the color temperature refers to the radiant energy transmitted by white. Color coordinates are the X and Y coordinates on the chromaticity diagram of wavelengths for the visible spectrum.

CONDITIONS

3.Click on the << or >> box next to B_CUT to set the “y” coordinate to 0.298 ± 0.02.

4.Click on the << or >> box next to R_CUT to set the “x” coordinate to 0.283 ± 0.02.

Note: If the above adjustments cannot be done to each coordinate, click on the

<<or >> box next to G_CUT to decrease or increase the green cutoff (bias) and repeat procedures 3 and 4.

Measurement instrument: Color analyzer

Scanning frequency:	68 kHz/85 Hz (17”)
	54 kHz/85 Hz (15”)
Display image:	White flat field at
	center of display area
Luminance:	Maximum

PROCEDURE

Use the directions in sections 5-4-2 through 5-4-3 to adjust the color coordinates for:

9300K to x = 0.283 ± 0.02,	y = 0.298 ± 0.02
6500K to x = 0.313 ± 0.02,	y = 0.329 ± 0.02

5-3-2 Color Adjustments for 9300K

5-3-2 (a) BACK RASTER COLOR ADJUSTMENT

CONDITIONS
Scanning frequency:	68 kHz/85 Hz (17”)
	54 kHz/85 Hz (15”)
Display image:	Back raster pattern
Brightness:	Maximum
Contrast:	Maximum
(for 17”)

5-3-2 (b) G-GAIN ADJUSTMENT

1/3H-1/2H

FRONT BEZEL OPENING

BACK RASTER

1/3V-1/2V

GREEN WINDOW

Figure 5-8. Green Box Pattern

CONDITIONS
Scanning frequency:	68 kHz/85 Hz (17”)
	54 kHz/85 Hz (15”)
Display image:	Green box pattern
Brightness:	Maximum
Contrast:	Maximum

1.Click on the << or >> box next to G_GAIN to adjust the brightness of the Green Gain to

40 ± 1 ft-L.

Note: If you can’t increase the Green Gain to the appropriate value, click on the >> box next to increase the ABL point.

1.Select COLOR CHANNEL 1 to control the color for 9300K.

2.Adjust the luminance of the back raster to between 0.5 to 0.7 ft-L using the G_CUT controls.

3.Click on the << or >> box next to B_CUT to set the “y” coordinate to 0.298 ± 0.02.

4.Click on the << or >> box next to R_CUT to set the “x” coordinate to 0.283 ± 0.02.

(for 15”)

1.Select COLOR CHANNEL 1 to control the color for 9300K.

2.Adjust the luminance of the back raster to between 0.5 to 0.7 ft-L using the Screen VR (T501) controls.

5-3-2 (c) WHITE BALANCE ADJUSTMENT

CONDITIONS
Scanning frequency:							68 kHz/85 Hz (17”)
							54 kHz/85 Hz (15”)
Display image:							Full white pattern
Brightness:							Maximum
Contrast:							Maximum
										FRONT BEZEL OPENING
										BACK RASTER
										WHITE WINDOW

Figure 5-9. Full White Pattern

5-6	CKB5237L/7227L