Casio TV-M430S, Руководство по обслуживанию и список запасных частей

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5. Bright, Contrast adjustment
•
Condition
(1) Signal
Broadcasting system: B/G
Color system: PAL color bar
(2) Signal level
Input electric field: 70 dB
µ
(75
Ω
termination), P/S = 10 dB
(3) Other conditions
CCIR IF input (input electric field should be terminated with 75
Ω
resistance).
Use VIDEO signal equivalent to TG7.
Power supply: VCC1-1(P105) = 13.50
±
0.05 [V]
•
Adjustment
(1) Connect the KILLER terminal (P307) to GND (P300).
(2) Adjust the contrast VR502 so that the waveform of the VG-output (P502) from the pedestal to white 75%
becomes 2.30
±
0.05 [V].
(3) Trigger the VG-output (P502) waveform at FRP signal (P703) and adjust the bright VR511 so that the
waveform from the pedestal to the 6 step becomes 0.80
±
0.05 [V].
NOTE: There are two adjustment positions. If adjusted at the wrong positions, the pedestal may fluctuate.
•
Caution
(1) RGB_AMP setting becomes maximum gain by chip jumper.
(2) BRT short pad (P510) is open.
(3) Carry out the adjustment so that the level of the inversion (black) and noninversion (white) waveforms
become equal at gray scale.
•
Block diagram
Oscilloscope
L-PCB
VG output
VCC1-1
IF signal
Signal
generator
Stabilizer
2.30V
0.80V
6. Current consumption check
•
Condition
(1) Signal Broadcasting system: B/G
Color system: PAL color bar
(2) Signal level Input electric field: 70 dB
µ
(75
Ω
termination), P/S = 10 dB
(3) Other conditions
RF input : voluntary CH
Audio volume : MAX
Bright volume : voluntary
Power voltage is 14.00
±
0.10 [V] (DC IN).
•
Adjustment
Carry out this adjustment to the product (assembled state).
The maximum value of the current consumption is 486 [mA] (satuated state for the product).