Samsung CF21M Alignment and Adjustments

4 Alignment and Adjustments

This section of the service manual explains how to make permanent adjustments to the monitor.

4-1 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.

4-1-1 Before Making Adjustments

4-1-1 (a) ORIENTATION

When servicing, always face the monitor to the east.

4-1-1 (b) 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.

4-1-1 (c) SIGNAL

Analog, 0.7 Vp-p positive at 75 ohm, internal termination Sync: Separate/Composite (TTL level negative/positive)

Sync-on-Green: Composite sync 0.3 Vp-p negative (Video 0.7 Vp-p positive)

4-1-1 (d) SCANNING FREQUENCY

Horizontal: 30 kHz ~ 115 kHz (Automatic) Vertical: 50 Hz ~ 160 Hz (Automatic)

Unless otherwise specified, adjust at the 1280 x 1024 mode (H: 91 kHz, V: 85 Hz) signals.

Refer to Table 2-1 on pages 2-2 and 2-3.

4-1-1 (e) HIGH VOLTAGE ADJUSTMENT

Signal: 1280 x 1024 mode (91 kHz/85 Hz) Display image: Full white Contrast: Maximum Brightness: Maximum Limit: 27.5 kV ± 0.5 kV

Measure the hight voltage level at the anode cap. High voltage should be within the limit as above.

4-1-1 (f) G2 (SCREEN) VOLTAGE

The Screen Voltage is fixed in the firm so don’t need to adjust the Screen voltage.

4-1-1 (g) CENTER RASTER

Adjust VR401 so that the back raster comes to the center when you apply a signal of 91 kHz/85 Hz.

4-1-2 Required Equipment

The following equipment may be necessary for adjustment procedures:

4-1-2 (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: 1280 x 1024 @ 85 Hz, or 1600 x 1200 @ 85 Hz (maximum).

6. Personal computer

4-1-2 (b) COLOR ADJUSTMENTS

1. All equipment listed in 4-1-2 (a), above

2. Color analyzer, or any luminance measurement equipmen

4-1-3 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.

CF21M* 4-1

4 Alignment and Adjustments

4-2 Display Control Adjustments

4-2-1 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: 312 mm (H) x 234 mm (V). 1280 x 1024 mode (91 kHz/85Hz)

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.

DISPLAY AREA

Figure 4-3. Centering

4-2-1 (a) HORIZONTAL SIZE ADJUSTMENT

CONDITIONS

Scanning frequency: 91 kHz / 85 Hz Display image: Crosshatch pattern Brightness: Cut-off Contrast: Maximum

Click on the << or >> box next to SIZE B+ to adjust the horizontal size of the display pattern to 312 mm (Tolerance: ± 3 mm) as the “H_SIZE” is “62” on the OSD.

4-2-1 (b) VERTICAL SIZE ADJUSTMENT

CONDITIONS

Scanning frequency: 91 kHz /85 Hz Display image: Crosshatch pattern Brightness: Cut-off Contrast: Maximum

Click on the << or >> box next to V_SIZE to adjust the vertical size of the display pattern to 234 mm. (Tolerance: ± 3 mm.)

4-2-1 (c) HORIZONTAL POSITION ADJUSTMENT

CONDITIONS

Scanning frequency: 91 kHz / 85 Hz Display image: Crosshatch pattern Brightness: Cut-off Contrast: Maximum

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

EDGE OF BEZEL

4-2-1 (d) VERTICAL POSITION ADJUSTMENT

CONDITIONS

Scanning frequency: 91 kHz / 85 Hz Display image: Crosshatch pattern Brightness: Cut-off Contrast: Maximum

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

4-2-2 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 Table 4-1 an image appears distorted, elongated or squashed.

Horizontal Linearity = 2x x100

Vertical Linearity = 2x x100

Preset mode

Pre-load mode (48kHz~) ≤ 5% ≤ 10%

Pre-load mode (under 48kHz) ≤ 5% ≤ 14%

❈ Preset Mode : 91 KHz / 85 Hz

Pre-load Mode : Refer to Timing Chart

4-2-2 (a) HORIZONTAL LINEARITY ADJUSTMENT

CONDITIONS

Scanning frequency: 91 kHz / 85 Hz Display image: Crosshatch pattern Brightness: Cut-off Contrast: Maximum

To adjust the Horizontal Linearity, refer to Table 4-1 for the tolerance range.

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

(Horizontal x Vertical Size Table)

Horizantal 393

Vertical 294.5

X max-X min

X max+X min

Y max-Y min

Y max+Y min

Table 4-1

Adjacent Linearity

≤ 4% ≤ 8%

Table 4-2

Entire Linearity

21”

4-2 CF21M*

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