Sony HCD-ZX70DVD, Руководство по обслуживанию, Страница: 115 / 136

17
5. ELECTRICAL ADJUSTMENTS
DECK SECTION 0 dB=0.775V
1. Demagnetize the record/playback head with a head demagne-
tizer.
2. Do not use a magnetized screwdriver for the adjustments.
3. After the adjustments, apply suitable locking compound to the
parts adjusted.
4. The adjustments should be performed with the rated power sup-
ply voltage unless otherwise noted.
5. The adjustments should be performed in the order given in this
service manual. (As a general rule, playback circuit adjustment
should be completed before performing recording circuit adjust-
ment.)
6. The adjustments should be performed for both L-CH and R-CH.
7. Switches and controls should be set as follows unless otherwise
specified.
4. After the adjustments, apply suitable locking compound to the
parts adjusted.
Adjustment Location: Playback Head (Deck A)
Record/Playback/Erase Head (Deck B)
3. Mode: Playback
Test tape
P-4-A100
(10kHz, –10dB)
Oscilloscope
MAIN
board
CN301
Set
Waveform of oscilloscope
in phase 45
°
90
°
135
°
180
°
Good
Wrong
2
1
3
L
R
R-CH
V H
Reverse Forward
Record/Playback Head Azimuth Adjustment
(Deck A, Deck B)
Note: Perform this adjustments for both decks.
Procedure:
1. Mode : Playback
2. Turn the adjustment screw and check output peaks. If the peaks
do not match for L-CH and R-CH, turn the adjustment screw so
that outputs match within 1 dB of peak.
Test tape
P-4-A100
(10kHz, –10dB)
MAIN board
CN301
1
(L-CH),
CN301
3
(R-ch)
Level meter
Set
+
–
MAIN board
CN301
2
(GND)
L-CH
peak
R-CH
peak
Screw
position
Output
level
Within
1 dB
L-CH
peak R-CH
peak
Screw
position
Within 1dB
Signal Used for
Tape
P-4-A100
WS-48B
P-4-L300
10 kHz, –10 dB
3 kHz, 0 dB
315 Hz, 0 dB
Azimuth Adjustment
Tape Speed Adjustment
Level Adjustment