Service manual

5-46
3-3. SERVO SYSTEM ADJUSTMENTS
1. CAP FG Offset Adjustment (VC-215 board)
Improve the capstan servo characteristic. If it is not correct. jitters
will increase.
Mode Camera recording (SP mode)
Subject Arbitrary
Measurement Point Pin !™ of CN910 (CAP FG)
Measuring Instrument Oscilloscope
Adjustment Page F
Adjustment Address 69
Specified value Duty = 50±0.5%
Adjusting method:
1) Select page: 0, address: 01, and set data: 01.
2) Select page: 2, address: 01, and set data: 81, and press the PAUSE
button of the adjustment remote commander. (to start up
automatic CAP FG offset adjustment.)
3) Select page: 2, address: 02, and check that the data is “01”.
4) Check that Duty of CAP FG signal satisfies the specified value.
If not, select page: 2, address: 01, set data: 00, and press the
PAUSE button, and then, repeat steps 2) to 4).
5) Select page: 2, address: 01, and set data: 00, and press the PAUSE
button of the adjustment remote commander.
6) Select page: 0, address: 01, and set data: 00.
2. RF Switching Position Adjustment (VC-215 Board)
If deviated in this case causes switching noise or jitter on the played
back screen.
Mode Playback
Signal Alignment tape:
For tracking adjustment
WR5-1NP
Measurement Point CH1: Pin !¡ of CN910 (RF SWP)
CH2: Pin 6 of CN910 (PB RF)
Measuring Instrument Oscilloscope
Adjustment Page F
Adjustment Address 7C (upper digits), 7D (lower digits)
Specified Value t1 = 0±10µsec
Adjusting Method:
1) Select page: 0, address: 01, and set data: 01.
2) Select page: F, address: 2A, and set data: 20, and press the PAUSE
button of the adjustment remote commander.
3) Select page: F, address: 7C, change the data and minimize “t1”,
and then press the PAUSE button of the adjustment remote
commander. (Coarse adjustment)
4) Select page: F, address: 7D, change the data and adjust so that
the switching position (t1) becomes the specified value. (Fine
adjustment)
5) Press the PAUSE button of the adjustment remote commander.
6) Select page: F, address: 2A, and set data: 00, and press the PAUSE
button of the adjustment remote commander.
7) Select page: 0, address: 01, and set data: 00.
Fig. 5-3-5.
Fig. 5-3-6.