CMT-EP303, HCD-EP303 - Sony Audio Service Manual (repair manual). Page 12

12

1.

Clean the following parts with a denatured-alcohol-moistened
swab :

record/playback head

pinch roller

erase head

rubber belts

capstan

idlers

2.

Demagnetize the record/playback head with a head
demagnetizer. (Do not bring the head magnetizer close to the
erase head.)

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.

FWD

CQ-403A

more than 100 g

(more than 3.53 oz)

1.

Setting
MEGA BASS switch : OFF

0 dB=0.775 V

2.95 – 6.86 mN•m

FWD

CQ-102C

(30 – 70 g•cm)
(0.42 – 0.97 oz•inch)

0.15 – 5.39 mN•m

FWD

CQ-102C

(1.5 – 5.5 g•cm)

Back Tension

(0.021 – 0.076 oz•inch)

more than 5.89 mN•m

FF

CQ-201B

(more than 60 g•cm)
(more than 0.83 oz•inch)

more than 5.89 mN•m

REW

CQ-201B

(more than 60 g•cm)
(more than 0.83 oz•inch)

WS-48A

3 kHz, 0 dB

Tape Speed Adjustment

P-4-A063

6.3 kHz, –10 dB

Head Azimuth Adjustment

Procedure:
1.

Mode: Playback

level meter

test tape 
P-4-A063
(6.3 kHz, –10 dB)

set

HEADPHONE board
PHONES jack (JK401)

32 

Ω

+
–

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 1dB of peak.

3.

Mode: Playback

4.

After the adjustments, apply suitable locking compound to the
parts adjusted.

Screw
position

L-CH
peak

within
1dB

Output
level

L-CH
peak

R-CH
peak

within
1dB

Screw
position

R-CH
peak

test tape 
P-4-A063
(6.3 kHz, –10 dB)

L-CH

R-CH

HEADPHONE board
PHONES jack (JK401)

oscilloscope

V

H

+ +

–

–

screen pattern

in phase

good

wrong

45 

°

90 

°

135 

°

180 

°

32 

Ω

32 

Ω

set