Samsung CKG7507 Alignment and Adjustments

6-1-1 Before Making Adjustments
6-1-1 (a) ORIENTATION
When servicing, always face the monitor to the east.
6-1-1 (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.
6-1-1 (c) WARM-UP TIME
The monitor must be on for 30 minutes before starting alignment. Warm-up time is especially critical in color temperature and white balance adjustments.
6-1-1 (d) SIGNAL
Analog, 0.714 Vp-p positive at 75 ohm, internal termination Sync: Separate/Composite (TTL level negative/positive)
Sync-on-Green: Composite sync 0.286 Vp-p negative (Video 0.714 Vp-p positive)
6-1-1 (e) SCANNING FREQUENCY
Horizontal: 30 kHz to 70 kHz (Automatic) Vertical: 50 Hz to 160 Hz (Automatic)
Unless otherwise specified, adjust at the 1024 x 768 mode (H: 60 kHz, V: 75 Hz) signals.
Refer to Table 2-1 on page 3-3.
6-1-1 (f) HIGH VOLTAGE ADJUSTMENT
Signal: No signal Display image: Self raster Contrast: Maximum Brightness: Maximum Limit: 26 kV ± 0.5 kV
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.
6-1-1 (g) G2 (SCREEN) VOLTAGE ADJUSTMENT
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 430 V ± 10 V.
6-1-1 (h) HORIZONTAL FREE-RUN FREQUENCY ADJUSTMENT
Signal: 60 kHz/75 Hz Contrast: Maximum Brightness: Maximum
Connect the Frequency counter probe to the H-DY (Red wire). Conncet pin 26 of IC401 to the Ground. Adjust VR 402 to 58.7 kHz ± 10 Hz.
6-1-1 (I) CENTER RASTER
Adjust SW401 so that the back raster comes to the center when you apply a signal of 60 kHz/75 Hz.
CKG7507L 6-1
6 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).
6-1 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.
6-1-1 (J) BRIGHTNESS AND CONTRAST
Unless otherwise specified, adjust external VRs: Brightness: Maximum (turn knob fully clockwise)
Contrast: Maximum (turn knob fully clockwise)
6-1-2 Required Equipment
The following equipment may be necessary for adjustment procedures:
6-1-2 (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 @ 75 Hz, or 800 x 600 @ 75 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
6-1-2 (b) COLOR ADJUSTMENTS
1. All equipment listed in 6-1-2 (a), above
2. Color analyzer, or any luminance measurement equipment
6-1-3 Connecting the SoftJig
Connect the monitor to the signal generator and/ or PC as illustrated in Figures 6-1 and 6-2.
Refer to Softjig Manual.
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.
6-1-4 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.
6 Alignment and Adjustments
6-2 CKG7507L
MONITOR
INTERFACE BOARD VER. 2.0
PC
SIGNAL GENERATOR
3-WIRE CABLE
SIGNAL CABLE
5V DC ADAPTOR
PARALLEL CABLE
Figure 6-1. Setup 1, With Signal Generator
MONITOR
INTERFACE BOARD VER. 2.0
PC
3-WIRE CABLE
SIGNAL CABLE
PARALLEL CABLE
D-SUB CONNECTOR
5V DC ADAPTOR
Figure 6-2. Setup 2, Without Signal Generator
6 Alignment and Adjustments
CKG7507L 6-3
6-2 Using the SoftJig
Refer to Softjig Manual.
6-3-1 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).
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.
Figure 6-3. Centering
6-3-1 (a) HORIZONTAL SIZE ADJUSTMENT CONDITIONS
Scanning frequency: 60 kHz/75 Hz Display image: Crosshatch pattern Brightness: Maximum Contrast: Maximum
Click on the << or >> box next to H_SIZE to adjust the horizontal size of the display pattern to 306 mm. (Tolerance: ± 3 mm.)
Caution: Must be adjusted first of all the
H_SIZE to 306 mm ± at VGA2 (31 kHz/70 Hz). Because all mode variable H_SIZE range is based on the adjusted factory data of VGA2.
6-3-1 (b) VERTICAL SIZE ADJUSTMENT CONDITIONS
Scanning frequency: 60 kHz/75 Hz 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. (Tolerance: ± 3 mm.)
6-3-1 (c) HORIZONTAL POSITION ADJUSTMENT CONDITIONS
Scanning frequency: 60 kHz/75 Hz Display image: Crosshatch pattern
Click on the << or >> box next to H_POSI to center the horizontal image on the raster.
6-3-1 (d) VERTICAL POSITION ADJUSTMENT CONDITIONS
Scanning frequency: 60 kHz/75 Hz Display image: Crosshatch pattern
Click on the << or >> box next to V_POSI to center the vertical image on the raster.
6-3-2 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 6-2 and 6-3, an image appears distorted, elongated or squashed.
Table 6-1. Standard Modes Linearity: 640x480/75Hz,
800x600/85Hz and 1024x768/85Hz
Table 6-2. Other Modes Linearity: VGA, SVGA, XGA,
MAC, etc.
6-3-2 (a) HORIZONTAL LINEARITY ADJUSTMENT
The CKG7507L/LM monitors offer only Vertical Linearity adjustments. Horizontal Linearity is fixed on the Chassis and is not adjustable.
6 Alignment and Adjustments
6-4 CKG7507L
6-3 Display Control Adjustments
C
A
DISPLAY AREA
EDGE OF BEZEL
B
D
4 : 3
5 : 4
Horizontal: 17.8~20.5 Vertical : 17.8~20.5
Horizontal: 16.7~19.2 Vertical : 17.8~20.5
Supported Timing Mode
Each block (14 %)
Difference between
adjacent blocks (5 %)
Horizontal: Less than 0.96 mm Vertical : Less than 0.96 mm
Horizontal: Less than 0.90 mm Vertical : Less than 0.96 mm
4 : 3
5 : 4
Horizontal: 18.2~20.1 Vertical : 18.2~20.1
Horizontal: 17.1~18.9 Vertical : 18.2~20.1
Standard Modes Linearity
Each block (10 %)
Difference between
adjacent blocks (4 %)
Horizontal: Less than 0.77 mm Vertical : Less than 0.77 mm
Horizontal: Less than 0.72 mm Vertical : Less than 0.77 mm
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