Sharp VC-A30G Serviceanleitung Seite 34

VC-A30G(BR) VC-A30S(BR)
VC-A30GM(BR) VC-A30SM(BR)
VC-A30QM(BR) VC-A30SV(8R)
Adjustment of slow tracking preset
instrument
Recording and playback
on self-recording tape.
Input signal Commercial broadcast or
video signal (external
input selector switch)
Adjusting point Tracking control
button (+), (-)
Specification No noise bar on the
monitor TV screen
1. Receive a commercial broadcast signal, or feed
the video signal to the video input terminal (with
the external input selector switch).
2. Press the slow button and play back the recorded
portion in the slow mode.
3. Make D5003 (cathode side) in Timer Unit and pin
@ of IC5001 short-circuited and check that the
fluorescent display tube light up.
4. Make D5003 and pin @ of IC5001 circuited and
check that the fluorescent display tube indicates
"CASS".
5. Observing the monitor screen, adjust the
tracking control button until the noise bar
disappears form the screen.
ADJUSTMENT OF Y/C CIRCUIT
6. Press the playback button to play back the tape.
Then push the pause/still button to reproduce
the recording in the still mode. Now make sure
there is no noise on the screen. (Repeat this step
three times or so.)
Adjustment of still picture vertical sync (FV)
Monitor TV
Still picture playback
Self-recording tape
Tracking control button
(+),(-)
No vertical jitter
1. Play back the tape self-recorded.
2. Press the pause/still button to reproduce the
recording in the still mode.
3. Observing the monitor screen, adjust the
tracking contro! button until the vertical jitter
disappears form the screen.
4. Then play the tape self-recorded and make sure
there is no vertical jitter on the monitor screen.
Measuring
instrument
Tape used
Test point
Adjusting point
Specification
ef LEV '
asor
30 co 2 22 ed 1s 1a 7 .
Figure 2-3. Y/C PWB
M@ ADJUSTMENT OF Y/C RECORDING CIRCUIT
Adjustment of EE level
Oscilloscope
[Mode =i Recording
Input signal Standard colour bar
(stair-case waveform)
Measuring
instrument
Pin © of !C201
R203 (EE level control)
2.0 + 0.1 Vp-p
34
1. Set the unit in record mode.
2. Feed the colour bar signal to the video input
terminal. Observe the voltage of the pin © of
1C201 on the oscilloscope screen, adjust R203 (EE
level control) to obtain the value indicated in
Figure 2-4.
Figure 2-4.