Sharp 37GT-28FP Service Manual page 9

Pal / secam system colour television
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5.5. Push "GREEN" button on R/C (to exit Bus Stop Mode).
5.6. Switch set OFF and ON again, setting is now memorized.
Screen Adjustment
1. Focus Adjustment
1.1. Apply mains voltage of 220V AC/50HZ to TV.
1.2. Receive Philips pattern signal to a level between 60 and 80 dB/uV.
1.3. Set contrast to 10/10, brightness to 5/10 and colour 0/10.
1.4. Adjust focus potentiometer to obtain maximum definition.
2.G2 Adjustment
2.1. Apply mains voltage of 220V AC/50HZ to TV.
2.2. Receive the "Cross Hatch" pattern signal to a level between 60 and 80 dB/uV.
2.3. Apply High Voltage Probe to Pin 8 of CRT socket
2.4. Adjust G2 potentiometer until obtaining 525V ±10%.
2.5. Check BKGD. If it is necessary adjust BKGD according to instructions detailed below.
Geometry Adjustment Procedure
1. Horizontal Shift
1.1. Receive Philips pattern signal.
1.2 Select H-SHFT with channel up or channel down buttons.
1.3. When volume up button is pressed, picture moves to the left.
1.4. When volume down button is pressed, picture moves to the right.
1.5. Adjust the horizontal location to obtain picture centering (Fig.2).
2. Vertical Shift
2.1. Receive Philips pattern signal.
2.2. Select V-SHFT with channel up or channel down buttons.
2.3. When volume up button is pressed, picture moves up.
2.4. When volume down button is pressed, picture moves down.
2.5. Adjust the vertical location to obtain picture centering (Fig.3).
3. Vertical Amplifier
3.1. Receive Philips pattern signal.
3.2. Select V-AMPL with channel up or channel down buttons.
3.3. When volume up button is pressed, vertical size of picture increases.
3.4. When volume down button is pressed, vertical size of picture decreases.
3.5. Adjust the vertical size to obtain picture overscan (Fig.4).
Colour Adjustment (BKGD) Procedures
The following adjustments are required when the Picture Tube or IC801 are replaced, or may be nec-
essary after adjustment of the G2 voltage.
1. «B-GAIN», «G-GAIN»
1.1. Adjust G2.
1.2. Tune a grey scale pattern.
1.3. Adjust colour to minimum.
1.4. Fix R-GAIN value to 32.
1.5. Position colorimeter in the left point of Fig.5.
1.6. Using brightness and contrast buttons, select a luminance of »120 nits.
1.7. Operate again in Service Mode and select location B-GAIN and G-GAIN to obtain colour coordinates:
X = 0.290 ± 0.015
Y = 0.284 ± 0.015
9
37GT-28FP
Fig. 2
Fig. 3
Fig. 4
6 5 4
Gain point
Fig. 5
3 2
1 0
DC point

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