HCD-ZX70DVD - Sony Audio Service Manual (repair manual). Page 18

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Note: Set the test mode using the following method and begin tape

speed adjustment.
In the test mode, the speed will switch to double speed or
normal speed each time the HI-DUB button is pressed.

Procedure:
With the power turned ON, press the  x  button,  DISPLAY  button,
and  DISC 3  button simultaneously.
(The  “TEST MODE” on the fluorescent indicator tube will be
displayed while in the test mode.)
To exit the test mode, press the  "/1  button.

1. Insert the WS-48B into deck B.
2. Press the  N  button of deck B.
3. Press the HI-DUB button and play the tape at double speed.
4. Adjust RV1001 of the LEAF SW board so that the reading of

the frequency counter becomes 6000 ± 180 Hz.

5. Press the HI-DUB button and play the tape at normal speed.
6. Adjust RV1002 of the LEAF SW board so that the reading of

the frequency counter becomes 3000 ± 90 Hz.

Deck A is RV311 (L-CH) and RV411 (R-CH), deck B is RV301
(L-CH) and RV401 (R-CH) so that adjustment within the following
adjustment level.

Adjustment level:
CN301 playback level: 301.5 to 338.3 mV (–8.2 to –7.2 dB)
level difference between the channels: within ± 0.5 dB
Adjustment Location: AUDIO board

Test tape 
P-4-L300
(315Hz, 0dB)

Level meter

Set

MAIN board
CN301 

1

 (L-CH),

CN301 

3

 (R-CH)

+

–

RV1002 Tape Speed (Normal)

RV1001 Tape Speed (High)

INTRODUCTION
When set to the test mode performed in 

,

when the tape is rewound after recording, the “REC memory

mode” which rewinds only the recorded portion and playback is
set.
This “REC memory mode” is convenient for performing this ad-
justment. During recording, the input signal FUNCTION will auto-
matically switch to VIDEO.
(After recording, press the  m  button without stopping will re-
turn to the position where recording was started)

1. Press  FUNCTION  button to select VIDEO. (This step is not

necessary if the above test mode has already been set)

2. Insert a tape into deck B, press the  REC PAUSE/START  button,

and then press the  N  button of deck B to start recording.

3. Mode: Record

5. Confirm playback the signal recorded in step 2 become adjust-

ment level as follows.
If these levels do not adjustment level, adjust the RV341 (L-CH)
and RV441 (R-CH) on the AUDIO board to repeat steps 3 and 4.

Adjustment level: The playback output of 10 kHz level difference

against 315 Hz reference should be ± 1.0 dB.

Adjustment Location: AUDIO board

4. Mode: Playback

Recorded
position

Level meter

Set

MAIN board
CN301 

1

 (L-CH),

CN301 

3

 (R-CH)

+

–

AF OSC

Blank tape
CS-123

Set

Attenuator

600 

Ω

VIDEO (AUDIO) IN
1) 315 Hz
2) 10 kHz

  50 mV (–23.8 dB)







W.RMS (JIS) less than 0.3%
(test tape: WS-48B)

Procedure:
Mode: Playback