SAMSUNG 793DF Service Manual Alignment & Adjustment

4 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).

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 (TTL level negative/positive)

4-1-1 (d) SCANNING FREQUENCY

Horizontal : Horizontal : Horizontal : Vertical : 50 Hz to 120 Hz (15” Automatic) Vertical : 50 Hz to 160 Hz (17” Automatic)

Unless otherwise specified, adjust at the 800 x 600 mode (15” 54 kHz/85 Hz), 1024 x 768 mode (17” 68 kHz/85 Hz), Refer to Table 2-1 on page 2-3.

30 kHz to 54 kHz (15” Automatic) 30 kHz to 70 kHz (17” 70kHz Automatic) 30 kHz to 85 kHz (17” 85kHz Automatic)

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, 2.5, 3 mm

2. Non-metallic (+) screwdriver:

1.5, 2.5, 3 mm

3. Digital Multimeter (DMM), or Digital Voltmeter

4. Signal generator, or DM200 software

5. 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 equipment.

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.

LE15V*/LE17LS/LE17LT/ LE17KS/LE17KT/LE17JS/LE17JT

4-1

4 Alignment and Adjustments

4-2 Display Control Adjustments

4-2-1 HIGH VOLTAGE

Signal: 800 x 600 (15” 54 kHz/85 Hz)

1024 x 768 (17” 68 kHz/85 Hz) Display image: Don’t care Contrast: Minimum Brightness: Minimum Limit: 25.0 kV ± 0.3 kV (15”)

26.0 kV ± 0.3 kV (17”)

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

4-2-2 CENTER RASTER (17” 85kHz only)

Adjust SW401 so that the back raster comes to the center when you apply basic mode for 17”.

4-2-3 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: 267 mm (H) x 200 mm (V) : (15”)

312 mm (H) x 234 mm (V) : (17”).

Adjust the horizontal position and vertical position to ≤ 5.0 mm of the center point of the screen.

|A-B| ≤ 5.0 mm. |C-D| ≤ 5.0 mm.

* In Softjig window, “Geometry” has to be

selected for GD adjustment.

4-2-3 (a) HORIZONTAL SIZE ADJUSTMENT

DISPLAY AREA

EDGE OF BEZEL

Figure 4-1. Centering

Use control bar after selecting size B+ in the left Menu to adjust the horizontal size of the display, Pattern to 267mm(Tolerance : ±4mm.)(15”) Pattern to 312mm(Tolerance : ±4mm.)(17”)

Run the All Mode save in the Right Menu.

Caution : scannig times except for 800 x 600 (54 kHz/85 Hz) -> 15” 1024x768 (68kHz/85Hz) -> 17”.

4-2-3 (b) VERTICAL SIZE ADJUSTMENT

CONDITIONS

Scanning frequency: 54 kHz/85 Hz

Display image: Crosshatch pattern Brightness: Maximum Contrast: Maximum

Use control bar after selecting “V-SIZE” in left menu to adjust the vertical size of the display pattern to 200 mm.(Tolerance: ± 4 mm.) : 15”,

4-2-3 (c) HORIZONTAL POSITION ADJUSTMENT

CONDITIONS

Scanning frequency: 54 kHz/85 Hz : 15”

Display image: Crosshatch pattern

Use control bar after selecting “H-POSITION” in left menu to center the horizontal image on the raster.

4-2-3 (d) VERTICAL POSITION ADJUSTMENT

CONDITIONS

Scanning frequency: 54 kHz/85 Hz : 15”

Display image: Crosshatch pattern

Use control bar after selecting “V-POSITION” in left menu to center the vertical image on the raster.

Do not Run the All mode Save at the other

68 kHz/85 Hz

234 mm.(Tolerance: ± 4 mm.) : 17”

68 kHz/85 Hz : 17”

CONDITIONS

Scanning frequency: 54 kHz/85 Hz (15”)

68 kHz/85 Hz (17”) Display image: Crosshatch pattern Brightness: Maximum Contrast: Maximum

Click Standard Dump on the right Menu in the general field.

4-2 LE15V*/LE17LS/LE17LT/

LE17KS/LE17KT/LE17JS/LE17JT

4 Alignment and Adjustments

4-2-4 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 4-2 and 4-3, an image appears distorted, elongated or squashed.

Table 4-1. Standard Modes Linearity:

800 x 600 / 85Hz (15”)

Adjacent Linearity

Preset mode ≤ 4% ≤ 8%

Pre-load mode (48kHz~) ≤ 5% ≤ 14%

❈ Preset Mode : 54KHz / 85Hz

Pre-load Mode : Refer to Timing Chart

Table 4-2. Standard Modes Linearity:

1024 x 768 / 85Hz (17”)

Standard Modes Linearity

Each block (10 %)

4 : 3

Horizontal: 20.9~23.1 Vertical : 20.9~23.1

Horizontal: Less than 0.88 mm Vertical : Less than 0.88 mm

Entire Linearity

Difference between

adjacent blocks (4 %)

68 kHz/85 Hz : 17” Display image: Crosshatch pattern Brightness: Maximum Contrast: Maximum

Use control bar after selecting “TRAPEZOID” in left menu to make the image area rectangular.

| A - B | < 4 mm

Figure 4-2. Trapezoid

4-2-6 Pinbalance Adjustment

CONDITIONS

Scanning frequency: 54 kHz/85 Hz : 15”

68 kHz/85 Hz : 17” Display image: Crosshatch pattern Brightness: Maximum Contrast: Maximum

Table 4-3. Other Modes Linearity:

above 40 KHz(Hf) : 17”

Supported Timing Mode

Difference between

adjacent blocks (5 %)

Horizontal: Less than 1.10 mm Vertical : Less than 1.10 mm

4 : 3

Each block (14 %)

Horizontal: 20.5~23.5 Vertical : 20.5~23.5

Off Spec : Under 40 KHz (Hf)

4-2-4 (a) VERTICAL LINEARITY ADJUSTMENT

CONDITIONS

Scanning frequency: 54 kHz/85 Hz : 15”

68 kHz/85 Hz : 17” Display image: Crosshatch pattern Brightness: Maximum Contrast: Maximum

To adjust the Vertical Linearity, refer to Tables 4-2 and 4-3 for the tolerance range.

Use control bar after selecting “V-LINEARITY BAL” in left menu to optimize the image.

4-2-5 Trapezoid Adjustment

CONDITIONS

Scanning frequency: 54 kHz/85 Hz : 15”

D1 D2 D1

Figure 4-3. Pinbalance

Use control bar after selecting “PINBALANCE” in left menu to optimize the image.

4-2-7 Parallelogram Adjustment

CONDITIONS

Scanning Frequency: 54 kHz/85 Hz : 15”

68 kHz/85 Hz : 17” Display image: Crosshatch pattern Brightness: Maximum Contrast: Maximum

Use control bar after selecting “PARALLEL” in left menu to make the image area rectangular.

4 mm

Figure 4-4. Parallelogram

LE15V*/LE17LS/LE17LT/ LE17KS/LE17KT/LE17JS/LE17JT

4-3

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