CMT-VC1, HCD-VC1 - Sony Audio Service Manual (repair manual). Page 13

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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.

Repeat step 1 to 3 in playback (REV) mode.

5.

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

0 dB=0.775 V

Tape

Signal

Used for

P-4-A100

10 kHz, –10 dB

Azimuth Adjustment

Confirm each contents of this section first of all. If the results are
not satisfied, do the adjustment.

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

Procedure:
1.

Mode:  Playback

°

°

°

°

1. CD block basically constructed to operate without adjustment.  There-

fore, check each item in order given.

2. Use YEDS-18 disc (Part No.: 3-702-101-01) unless otherwise indicated.
3. Use the oscilloscope with more than 10 M

Ω

 impedance.

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

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

Procedure:
1. Connect an oscilloscope to IC703 pin qg and TP (VC) on the

CD board.

2. Connect between TP (FOK) and TP (GND) on the CD board

by lead wire.

3. Turn the power ON.
4. Press the

 [EJECT    ]

 (CD) button to open the disc tray, and

put the disc (YEDS-18).

5. Press the 

[EJECT    ]

 (CD) button to close the disc tray (Actu-

ate the focus search).

6. Confirm that the waveform on the oscilloscope is symmetrical

between A and B and that peak to peak level is within 3.0 

±

1.0 Vp-p.

S-curve waveform

7. After confirmation, disconnect the lead wire in step 2.

• Try to measure several times to make sure that 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 an oscilloscope to IC703 pin qh and TP (VC) on the

CD board.

2. Turn the power ON.
3. Load the disc (YEDS-18), and press the 

[    ]

 button to play-

back the disc.

4. Confirm that the waveform on the oscilloscope is clear and

that the RF signal level is correct.

Clear RF signal waveform means that the shape “

◊

” can be clearly

distinguished at the center of the waveform.

IC703 pin qg

IC703 pin qh

RF signal waveform

When observing the eye pattern, set the oscilloscope for AC range
and raise vertical sensitivity.

Z

within 3.0 

±

 1.0 Vp-p

u

Z