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Service Adjustments (Electronic Controls)
Sub-Contrast Adjustment
Serviceman DAC Adjustment (B02, B03)
This adjustment is factory set. Do not adjust unless
repairs are made to associated circuit, the CRT Board
or when the CRT is replaced.
Preparation:
1. Apply a Black-White pattern.
2. Set the picture settings to normal and color to
minimum.
3. RGB GAMMA (S03) DAC from 1 to 0
4. Connect the oscilloscope to TP47R.
5. Connect a jumper from TPD2 to cold ground ( ).
Procedure:
1. In the Serviceman Mode, select DAC B2 for Sub-
Brightness to obtain 2.6±0.1V between 7.5IRE and
GND level at TP47R (See Fig. 25)
2. In the Serviceman Mode, select DAC B03 for Sub-
Contrast to obtain 1.5±0.1V between 7.5IRE and
100IRE level at TP47G
3. Remove short jumper and set RGB GAMMA (S03)
DAC to 1.
4. Set the picture settings to normal.
.
Sub-Brightness (B02)
Adjustment of this control is important for setting proper
operation of customer brightness and picture controls.
Do not adjust the SCREEN VR after the Sub-
Brightness is set.
Preparation:
1. Normalize picture settings.
2. Switch COLOR TEMPERATURE to NORMAL.
Procedure:
1. Apply a black white cross pattern.
2. In the Serviceman Mode for making electronic
adjustments, select the DAC adjustment (B02) and
adjust data so that 7.5IRE part is the same light
output as the 3IRE part (See Fig. 26).
Tint/Color Adjustment
Serviceman DAC Adjustment (B01) (B00)
Preparation:
1. Apply a rainbow color bar signal.
2. Preset the following controls:
• Brightness . . . . . . . Min.
• Color . . . . . . . . . . . . Center.
• Tint . . . . . . . . . . . . . Center.
• Picture . . . . . . . . . . . Max.
• Sharpness . . . . . . . . Min.
3. Set RGB GAMMA (S03) DAC to 0
4. Connect the oscilloscope to TP47B (A-Board).
5. Connect a jumper from TPD2 to GND ( ).
Procedure:
1. In the Serviceman Mode for making electronic
adjustments, select (B01) DAC Sub-Tint
Adjustment. Adjust until the waveform measured is
as the one shown in Fig. 27.
2. Connect the oscilloscope to TP47G or TP35 (L-
Board) and cold GND.
3. Select DAC Sub-Color Adjustment (B00) and
adjust for peak to peak amplitude to be
0.50Vp-p ±0.05V as shown in Fig .28.
4. Remove short jumper and set RGB GAMMA (S03)
DAC to 1.
PIP Sub-Contrast Adjustment (P03)
100IRE
7.5IRE
GND
Figure 25. waveform
1.5
±
0.1V
2.6
v
±
0.1V
3 IRE
7.5 IRE
Figure 26. Pattern
A to B = 1 unit
A
C
1 2 3 10
4 5 6 7 8 9
B
B to C = 2 units
Figure 27. TP47B waveform
TP47B (A-Board)
A
1 2 3 4 5 6
7 8 9 10
Figure 28. TP47G waveform
TP47G (A-Board)
0.50Vp-p±0.05V