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PT-11 Chassis Service Manual
PT-11 CHASSIS
ADJUSTMENT
l-
System Voltage (+B) Adjustment
:
PROCEDURE
- Before switching on TV, all potentiometers should be adjusted at medium level. Then TV is switched on;
-
Adjust all of the analog parameters to minimum with RC
-
Adjust Pl trimpot until find +115 V on the cathode of D2 diode
2- AFT Adjustment:
-
Place a balloon coil (300 Ohm dc resistance
)
parallel to L104
-
Apply 80 dB UV 38.9 MHz (39.5 MHz for I
)
signal via balloon coil
-
Connect a voltmeter to aft pin (pin 9) of IC301
-
Adjust TlOl coil until the voltage of this pin being 2.5 V dc
3- Adjustment of G2:
-
Apply Philips Test pattern
-
Adjust all of the analog parameters to minimum with RC
-
Adjust G2 trimpot until seeing two bars on gray scale
4- Horizontal and Vertical Adjustment:
-
Apply Philips Test pattern signal
-
Center the picture horizontally while picture shifting to right and left with
Pl 01,
-
Make vertical amplitude adjustment with P602 until seeing top and lower lines of picture will be seen
-
Center the picture with P601
5-
AGC Adjustment:
-
Apply Philips Test Pattern whose amplitude is 60 dB UV to the rf input
-
Adjust P102 until find a picture without snowy
6- Focus Adjustment:
-
Apply Cross-Hatch Pattern signal
-
Find the optimum concentration point between H and V intersection in the middle of screen.
7- White Balance Adjustment
:
-
Apply Philips Test Pattern signal
-
Adjust all of the trimpots on CRT board to medium level
-
Adjust color, contrast, brightness to minimum by RC
-
Adjust G2
-
Apply white pattern, settle in the probe of color analyzer to screen
-
Increase brightness until geting Y=lO nits
-
Adjust x=270
-
276 nits y=270
-
276 nits via "VR201, VR203, VR205"
-
Increase brightness and contrast until Y=90
-
100 nits
-
Adjust x, y to same values via "VR202 and VR204"
-
Check white balance at high and low contrast level. Again make adjustment if it's necessary.
6
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