Casio EV-660C Service Manual page 15

8. VCOM DC adjustment
• Conditions
(1) Signals
Broadcasting system: I
Color system: PAL
(2) Signal: Provide any PAL signal from AV Jack.
(3) Others
Power supply should be Vcc1-1 = 5.00 ± 0.05V.
• Adjustment
Monitoring Photo sensor AMP output with an oscilloscope via 50Hz band-pass filter, adjust VCOM DC VR
(VR730) so that 50Hz ripple component is minimum.
• Caution
Perform this adjustment when you replaced the display module.
Use specified jig to replace photoelectric parts
• Block diagram
Photo diode
S1133
EV-660D
AV JACK
Signal
Stabilizer
generator
Photosensor amp.
C2719
VCC1-1
— 13 —
B.P.F.
Oscilloscope