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21

Precaution
1. Clean the following parts with a denatured alcohol-moistened

swab:
record/playback heads

pinch rollers

erase head rubber belts
capstan

idlers

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.

3.06 N • m to 6.96 N • m

31 to 71 g • cm

(0.43 – 0.98 oz • inch)

0.19 N • m to 0.58 N • m

2 to 6 g • cm

(0.02 – 0.08 oz • inch)

3.06 N • m to 6.96 N • m

31 to 71 g • cm

(0.43 – 0.98 oz • inch)

0.19 N • m to 0.58 N • m

2 to 6 g • cm

(0.02 – 0.08 oz • inch)

6.96 N • m to 14.02 N • m

71 to 143 g • cm

(0.98 – 1.99 oz • inch)

9.80 N • m

100 g or more

(3.53 oz or more)

9.80 N • m

100 g or more

(3.53 oz or more)

CQ-102C

CQ-102C

CQ-102RC

CQ-102RC

CQ-201B

CQ-403A

CQ-403R

FWD

FWD

back tension

REV

REV

back tension

FF/REW

FWD tension

REV tension

0 dB=0.775 V

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 adjust.

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.

• Test Tape

Note:  Perform this adjustments for both decks

Procedure:
1. Mode:  Playback

P-4-A100

10 kHz, –10 dB

Azimuth Adjustment

WS-48B

3kHz, 0 dB

Tape Speed Adjustment

set

MAIN board
CN301
Pin 

1

 (L-CH)

Pin 

3

 (R-CH)

MAIN board
CN301
Pin 

2

 (GND)

+
–

level meter

test tape
P-4-A100
(10 kHz, –10 dB)

22

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

pats adjusted.

Adjustment Location: Playback Head (Deck A).

Record/Playback/Erase Head (Deck B).

Screw
position

L-CH
peak

within
1dB

Output
level

L-CH
peak

R-CH
peak

within
1dB

Screw
position

R-CH
peak

MAIN
board
CN301
set

test tape
P-4-A100
(10 kHz, –10 dB)

pin 

3

oscilloscope

L-CH

R-CH

V

H

waveform of oscilloscope

in phase 45

°

90

°

135

°

180

°

good

wrong

pin 

2

pin 

1

L

R

forward

reverse

Tape Speed Adjustment
   DECK B
Procedure:
Mode: Playback

set

MAIN board
AUDIO OUT jack (J730)
L-CH, R-CH

+
–

frequency counter

test tape
WS-48B
(3 kHz, 0 dB)

1. Insert the WS-48B into the deck B.
2. Press the   H  button on the deck B.
3. Adjust the tape speed adjustment control inside motor so that

frequency counter reads 3,000 

± 90Hz.

Sample value of wow and flutter W.RMS (JIS) less than 0.3%
WS-48B

Tape speed adjustment
control inside motor

– MAIN BOARD (Component Side) –

CN301

IC301

3

1

23

Note :
1. CD Block is basically designed to operate without adjustment.

Therefore, check each item in order given.

2. Use LUV-P01 (4-999-032-01) unless otherwise indicated.
3. Use an oscilloscope with more than 10M

Ω impedance.

4. Clean the object lens by an applicator with neutral detergent

when the signal level is low than specified value with the
following checks.

BD board

Oscilloscope

TP(FE)
TP(DVC)

Procedure :
1. Connect oscilloscope to TP (FE).
2. Connect between TP (FE) and TP (DVC (   1.65 V)) by lead

wire.

3. Press the  \/1  button to turn the power ON.
4. Load a disc (LUV-P01) and actuate the focus search. (In conse-

quence of open and close the disc tray, actuate the focus search)

5. Confirm that the oscilloscope waveform (S-curve) is symmetri-

cal between A and B. And confirm peak to peak level within 2
±0.5 Vp-p.

symmetry

S-curve waveform

within 4 

±

1Vp-p

A

B

6. After check, remove the lead wire connected in step 2.
Note : • Try to measure several times to make sure than the ratio

  of A : B or B : A is more than 10 : 7.
• Take sweep time as long as possible and light up the
  brightness to obtain best waveform.

Procedure :
1. Connect oscilloscope to TP (RFDC) and TP (RFAC).
2. Press the  \/1  button to turn the power ON.
3. Load a disc (LUV-P01) and playback.
4. Confirm that oscilloscope waveform is clear and check RF

signal level is correct or not.

Note: Clear RF signal waveform means that the shape “◊” can be

       clearly distinguished at the center of the waveform.

VOLT/DIV : 200mV
TIME/DIV : 500ns

level : 1.45 

±

 0.3Vp-p

TP(TE)
TP(DVC)

BD board

oscilloscope

Procedure:
1. Connect oscilloscope to TP (TE) and TP (DVC) on BD board.
2. Press the  \/1  button to turn the power ON.
3. Load a disc (LUV-P01) and playback the number nine track.
4. Press the  bB  button. (Becomes the 1track jump mode.)
5. Confirm that the level B and A (DC voltage) on the oscillo-

scope waveform.

B=1.3 

±

 0.6Vp-p

symmetry

A (DC voltage)

center of
waveform

B

0V

Specified level:     

× 100=less than – 22%

B

A

DVC

RFDC

RFAC

TE

FE

SE

DVC

TP(RFDC)
TP(RFAC)

BD board

oscilloscope

24

Note :

1. VIDEO board is basically designed to operate without adjust-

ment. Therefore, check each item in order given.

2. Use HLV-402 (8-909-870-00) unless otherwise indicated.
3. Use an oscilloscope with more than 10M

Ω impedance.

4. Clean the object lens by an applicator with neutral detergent

when the signal level is low than specified value with the
following checks.

Video Level Check (VIDEO BOARD)
Purpose
This adjustment is made to satisfy the NTSC standard, and if not
adjusted correctly, the brightness will be too large or small.

Procedure:
1. Connect oscilloscope to VIDEO output.
2. Load a disc HLV-402 (8-909-870-00) playback.
3. Check that the video level is 1.0 

± 0.1 Vp-p.

J721
VIDEO OUTPUT

75 

Ω

Oscilloscope

set

1.0 ± 0.1 Vp-p

(WHITE 100%)