Sony RMT-V267B, Service Manual

Page: 67 / 91

6-3
2-3. SERVO SYSTEM ADJUSTMENT
2-3-1. RF Switching Position Adjustment
(MA-360 Board)
[Adjustment Purpose]
To adjust the link of the A-ch and B-ch of the tape playback outputs.
To make the unit compatible with other tapes and units. If this
specification is not satisfied, the link will appear on the screen and
the screen will be disrupted, etc.
Mode Playback
Signal Alignment tape:
SP mode color bar portion
Measurement Point CH1: VIDEO LINE OUT terminal
CH2: CN270 pin
3
(RF SWP)
Measuring Instrument Oscilloscope
Specified Value t = 413 ± 32
µ
sec (6.5 ± 0.5 H)
[Adjustment method]
1)
Connect JS161 (IC161 pin
%§
) (SW POS ADJ) and GND with
a jumper wire.
2) Check that “AP” indicator on the display window turns on.
3) Remove the jumper wire.
3) Press and CHANNEL– buttons and adjust the
switching position (t) to the specified value.
4) Press PAUSE button to write the data in EEPROM.
5) Check that the display changes to “AH” and mode goes to the
Hi-Fi switching position adjustment.
6) Perform “Hi-Fi Switching Position Adjustment”.
Fig. 6-2-3
2 V
CH1
CH2
Magnified
V sync
CH1
CH2
t
2-3-2. Hi-Fi Switching Position Adjustment
(MA-360 Board)
[Adjustment Purpose]
To adjust the link of the A-ch and B-ch of the tape playback outputs.
To make the unit compatible with other tapes and units. If this
specification is not satisfied, the switching noise will be heard, etc.
Mode Playback
Signal Alignment tape:
SP mode color bar portion
Measurement Point CH1: CN270 pin
1
(HF ADJ)
CH2: CN270 pin
3
(RF SWP)
Measuring Instrument Oscilloscope
Specified Value A = minimum
Note:
Perform “RF Switching Position Adjustment” before this adjustment.
[Adjustment method]
1)
Check that “AH” indicator on the display window turns on.
2) Press and CHANNEL– buttons and minimize
the part A of PB AF RF signal.
3) Press PAUSE button to write the data in EEPROM.
4) Check that the “AH” indicator turns off.
Fig. 6-2-4
A
A
2 V
CH1
CH2