DOWNLOAD Sony HCD-GNX600 / MHC-GNX600 Service Manual ↓ Size: 5.37 MB | Pages: 84 in PDF or view online for FREE

21

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 Head (Deck B).

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

Therefore, check each item in order given.

2. Use YEDS-18 disc (3-702-101-01) 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.

1. Connect an oscilloscope to test point JPO102 (FE1) and TP

117(VC) on the CD board.

2. Turn the power on.
3. Put the disc (YEDS-18) in and turned power switch on again

and actuate the focus search. (actuate the focus search when
disc table is moving in and out)

4. Check the oscilloscope waveform (S-curve) is symmetrical

between A and B. And confirm peak to peak level within
2.4 

±

 1 Vp-p.

S-curve waveform

•

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.

Checking Location: CD board (SIDE B)

(See page 23.)

azimuth
screw

+
–

CD board

JPO102 (FE1)

TP117 (VC)

oscilloscope

Screw
position

L-CH
peak

within
1dB

Output
level

L-CH
peak

R-CH
peak

within
1dB

Screw
position

R-CH
peak

MAIN
board
CN121
set

test tape
P-4-A100
(10 kHz, –10 dB)

pin 

1

oscilloscope

L-CH

R-CH

V

H

waveform of oscilloscope

in phase 45

°

90

°

135

°

180

°

good

wrong

pin 

2

pin 

3

L

R

A

B

symmetry

within 2.4 

±

 1 Vp-p

22

1. Connect an oscilloscope to test point TP124 (RFAC) and TP

117(VC) on the CD board.

2. Turn the power on.
3. Put the disc (YEDS-18) in to playback the number five track.
4. Confirm that oscilloscope waveform is clear and check RFAC

signal level is correct or not.

A clear RFAC signal waveform means that the shape “

◊

” can be

clearly distinguished at the center of the waveform.

       RFAC signal waveform

Checking Location: CD board (SIDE B)

(See page 23.)

1. Connect an oscilloscpe to test point TPO103 (TE1) and TP117

(VC) on the CD board.

2. Turn the power on.
3. Select the function “CD”.

                   

4. Press three buttons of [ENTER], M , and

[SURRUUND MODE]  simultaneously to set the CD service
mode.

5. Put the disc (YEDS-18) in to playback the number five track.

                

6. Press the  .    button. The message “TRAVERSE” is

displayed. (The tracking servo and the sledding servo are
turned OFF)

7. Check the level B of the oscilliscope's waveform and the A

(DC voltage) of the center of the Traverse waveform.
Confirm the following :
A/B x 100 = less than 

±

 22%

Traverse Waveform

                

8. Press the  .    button. The message “TRAVERSE” is

displayed. (The tracking servo and sledding servo are turned
ON)
Confirm the C (DC voltage) is almost equal to the A (DC
voltage) is step 5.

9. To exit from this mode, perform as follows.

1)

Move the optical pick-up to the most inside track.

                

2) Press three buttons of x , [CLEAR], and [DISPLAY]
simultaneously. (cold reset)

• Always move the optical pick-up to most inside track
when exiting from this mode. Otherwise, a disc will not
be unloaded.
• Do not run the sled motor excessively, otherwise the gear

can be chipped.

Traverse Waveform

Checking Location: CD board (SIDE B) (See page 23.)

+
–

CD board

TP124 (RFAC)

TP117 (VC)

oscilloscope

VOLT/DIV: 200 mV
TIME/DIV: 500 ns 

level: 0.9 

±

 0.4 Vp-p

+
–

CD board

JPO103 (TE1)

TP117 (VC)

oscilloscope

0V

B

level: 1.0 

±

 0.5 Vp-p

Center of 
the waveform

A (DC 

voltage)

0V

Tracking servo

Sled servo

ON

C (DC 
voltage)

Tracking servo

Sled servo

OFF

23

TP117 (VC)

TP124 (RFAC)

JPO103 (TE1)

JPO102 (FE1)

IC101

24

For schematic diagrams.
Note:
• All capacitors are in 

µ

F unless otherwise noted. (p: pF)

50  V or less are not indicated except for electrolytics and
tantalums.

• All resistors are in 

Ω

 and 

1

/

4

 

W or less unless otherwise

specified.

•

%

: indicates tolerance.

•

f

: internal component.

•

2

: nonflammable resistor.

•

5

: fusible resistor.

•

C

: panel designation.

•

A

: B+ Line.

•

B

: B– Line.

•

H

: adjustment for repair.

• Voltages and waveforms are dc with respect to ground

under no-signal conditions.
CD board
 no mark: CD PLAY
Other boards
 no mark: TUNER (FM/AM)
 (          )    : CD PLAY
 <

>   : TAPE PLAY

 [

]   : TAPE REC

  *

    : Impossible to measure

• Voltages are taken with a VOM (Input impedance 10 M

Ω

).

Voltage variations may be noted due to normal produc-
tion tolerances.

• Waveforms are taken with a oscilloscope.

Voltage variations may be noted due to normal produc-
tion tolerances.

•

Signal path.

F

: AUDIO

f

: TUNER (FM/AM)

E

: TAPE PLAY (DECK A)

d

: TAPE PLAY (DECK B)

G

: RECORD

J

: CD PLAY

N

: MIC INPUT

• Abbreviation

AR

: Argentina model

AUS

: Australian model

E2

: 120V AC Area in E model

E3

: 240V AC Area in E model

E51

: Chilean and Peruvian model

Note: The components identified by mark 

0

 or dotted line

with mark ! are critical for safety.
Replace only with part number specified.

(The other layers' patterns are not indicated.)

• Indication of transistor.

Caution:
Parts face side:

Parts on the parts face side seen from

(Side A)

the parts face are indicated.

Pattern face side:

Parts on the pattern face side seen from

(Side B)

the pattern face are indicated.

C

B

These are omitted.

E

Q

B

These are omitted.

C

E

Q

B

These are omitted.

C

E

Q

• X

: parts extracted from the component side.

•

: Pattern from the side which enables seeing.