Mechanical Adjustments; Electrical Adjustments - Sony HCD-GRX20 Service Manual

SECTION 4

MECHANICAL ADJUSTMENTS

Precaution
1. Clean the following parts with a denatured alcohol-moistened
swab:
record/playback head
erase head
capstan
2. Demagnetize the record/playback head with a head
demagnetizer.
3. Do not use a magnetized screwdriver for the adjustments.
4. After the adjustments, apply suitable locking compound to the
parts adjusted.
5. The adjustments should be performed with the rated power
supply voltage unless otherwise noted.
Torque Measurement
Torque Torque meter
FWD CQ-102C
FWD
CQ-102C
back tension
FF/REW CQ-201B
pinch rollers
rubber belts
idlers
Meter reading
40 to 70 g • cm
(0.56 - 0.97 oz • inch)
1 to 5 g • cm
(0.01 - 0.07 oz • inch)
55 to 140 g • cm
(0.76 - 1.94 oz • inch)
SECTION 5

ELECTRICAL ADJUSTMENTS

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.
Tape Signal
10 kHz, –10 dB
P-4-A100
WS-48B 3 kHz, 0 dB
Record/Playback Head Azimuth Adjustment
(Deck A, Deck B)
Note: Perform this adjustments for both decks.
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 2 dB of peak.
L-CH
output
peak
within
level
2dB
R-CH
peak
screw
position
L-CH
peak
Used for
Azimuth Adjustment
Tape Speed Adjustment
level meter
SPEAKER
terminal (JK401)
within 2dB
screw
R-CH
position
peak
11