Sony XVM-R75, Руководство по обслуживанию

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4
XVM-R75
1-17. VCOM BIAS ADJUSTMENT
1. Display gray scale on the monitor screen.
2. Connect oscilloscope to the Q15 No. 2.
3. Adjust the semi-fixed resistor VCDC until the levels A and B of
the output waveform stand at their respective specified values.
Specified value: A: 5.3 ± 0.04 V
B: 1.7 ± 0.04 V
1-18. BLANK LEVEL ADJUSTMENT
1. Display gray scale on the monitor screen. Set the screen to the
Normal mode.
Adjustment Location:
– DISPLAY BOARD – (CONDUCTOR SIDE)
C10
VR18
VR19
VR20
U705
Q15
Q701
VCDC
VCOM
VSUR
VRGB
VSUB
VBRI
U600
VLOW
VHIG
VCOL
VPIC
VTIN
VGA2 VGA1
VCNT
VFRER
L19
VR1
If not black on the right and left ends,
adjust VHIG and VLOW so that black
vertical bands appear on the right and
left ends of the screen.
2. Connect digital voltmeter to pin
8
of IC U602.
3. Adjust the semi-fixed resistor VHIG so that the reading on the
digital voltmeter is at less than 0.5 V.
4. Connect digital voltmeter to pin 2 of IC U602.
5. Adjust the semi-fixed resistor VLOW so that the reading on the
digital voltmeter is at more than 6.0 V.
A
GND level
B