Electrical Adjustments - Sony HCD-EP313 Service Manual

DECK SECTION 0 dB=0.775V
1. Demagnetize the record/playback head with a head demagnetizer.
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
supply 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
adjustment.)
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.
Tape Signal
P-4-A100 10 kHz, –10 dB
WS-48B 3 kHz, 0 dB
[Record/Playback Head Azimuth Adjustment]
Procedure:
1. Mode : Playback
test tape
P-4-A100
(10kHz, –10dB)
set
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.
L-CH
output
peak
within
level
1 dB
R-CH
peak
screw
position
SECTION 5

ELECTRICAL ADJUSTMENTS

Used for
Azimuth Adjustment
Tape Speed Adjustment
MAIN board
level meter
J203
speaker terminal
+
–
within 1dB
screw
L-CH R-CH
position
peak peak
3. Mode: Playback
test tape
P-4-A100
(10kHz, –10dB)
set
Waveform of oscilloscope
45 °
in phase
good
4. After the adjustments, apply suitable locking compound to the
parts adjusted.
Adjustment Location: Record/Playback/Erase Head
[Tape Speed Check]
Procedure:
1. Turn the power on.
2. Insert the WS-48B into deck.
3. Press the N button of deck.
4. Check the reading of frequency counter becomes 3000 ± 90 Hz.
Sample Value of Wow and flutter
W.RMS (JIS) less than 0.3%
(test tape: WS-48B)
Adjustment Location: Record/Playback Head.
adjustment screw
Note: Refer to "3-6. Cassette Door Assy" (see page 10)
HCD-EP313
MAIN board
J203
speaker terminal
oscilloscope
L
R
90 ° 135 ° 180 °
wrong
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