DOWNLOAD Sony CFD-6 Service Manual ↓ Size: 695.68 KB | Pages: 28 in PDF or view online for FREE

– 9 –

Procedure :
1. Mode : playback

test tape
P-4-A063
(6.3kHz, –10dB)

set

33

Ω

J302 (phones)

level meter

+

–

L-CH
peak

R-CH
peak

L-CH
peak

R-CH
peak

Screw
position

output
level

within

2dB

within

2 dB

screw position

2. Turn the adjustment screw for the maximum output levels. If
   these levels do not match, turn the adjustment screw until both
   of output levels match together within 2dB. 

3. Phase Check

Mode : playback

L-CH

H

V

L-CH

set

33

Ω

R-CH

R-CH

33

Ω

in phase     45

°

        90

°

       135

°

      180

°

good

wrong

screen pattern

test tape
P-4-A063
(6.3kHz, –10dB)

J302 (phones)

oscilloscope

+
–

+

–

Adjustment Location : – record / playback head –

adjustment screw

REC/PB head

Function switch

: AM

Volume

: MAX

AM RF signal
generator

30% amplitude modulation by 400Hz
signal.
Output level : as low as possible

Put the lead-wire
antenna close to 
the set.

Function switch

: FM

Volume

: MAX

FM RF signal
generator

22.5kHz frequency deviation by 
400Hz signal.
Output level : as low as possible

telescopic
antenna
terminal

0.01  F

µ

set

33

Ω

+

–

J302 (phones)

level meter

r

Repeat the procedures in each adjustment several times, and the

frequency coverage and tracking adjustments should be finally done
by the trimmer capacitors.

no mark

: E, Central & South America model

 [        ]

: AEP, UK model

((       ))

: Italian model

 <       >

: East European model

           Adjust for a maximum reading on level meter.

CFT1

455kHz

[ 455kHz]

(( 455kHz))

< 455kHz>

           Adjust for a maximum reading on level meter.

L4

520kHz

[520kHz]

((516kHz))

<520kHz>

CT4

1,680kHz

[1,680kHz]

((1,630kHz)) <1,680kHz>

          Adjust for a maximum reading on level meter.

L3

620kHz

[620kHz]

((620kHz))

<620kHz>

CT3

1,400kHz

[1,400kHz]

– 10 –

               Adjust for a maximum reading on level meter.

L2

86.5MHz

[87.0MHz] ((87.35MHz )) <64.0MHz>

CT2

109.5MHz

[108.3MHz] ((108.25MHz)) <109.5MHz>

            Adjust for a maximum reading on level meter.

L1

86.5MHz

[87.0MHz] ((87.35MHz )) <64.0MHz>

CT1

109.5MHz

[108.3MHz] ((108.25MHz)) <109.5MHz>

Adjustment Location : Tuner board (page 13)

FM RF signal
generator

set

0.01  F

Carrier frequency : 98MHz
Modulation : no modulation
Output level : 1.38mV (–55dB)

µ

telescopic
antenna
terminal

1. Connect the frequency counter to 4 and 7 pins of IC1 as shown

the figure below.

2. Turn the set to 98MHz.
3. Adjust RV1 for 76 kHz 

±

 500 Hz reading on frequency counter.

frequency counter

1 

 

F

33k

Ω

µ

+

Adjustment Location : Tuner board (page 13)

1. Perform adjustment in test mode.

After adjustment, be sure to release test mode.

2. Perform adjustments in the order given.
3. Use the disc (YEDS-18. Part No. 3-702-101-01) only when  so

indicated.

Put the set into test mode and perform the following checks.
Repair if there are any problems.

r

 Sled Motor Check

1. Press ^ button, then press OFF button.
2. Press +, =buttons and confirm that the Optical pick-up

moves smoothly from the innermost to outermost circumference
and back smoothly and with no catching or abnormal noises. (Can-
cellation of BTL mute)

+ : Optical pick-up moves to the outer circumference
= : Optical pick-up moves to the inner circumference

r

 Focus Search Check

1. Press ^ button. (Focus search operation is performed continu-

ously.)

2. Look at the Optical pick-up objective lens and confirm that it moves

up and down smoothly, with no catching or abnormal noises.

3. Press 

π

 button.

Confirm that focus search operation stops. If it does not , press 

π

button again longer.

: When the malfunction is occurred by mis-passing

other buttons, turn off the power and check again
from making the test mode.

1. Short-circuit following portion (IC801 @¢ pin) on the MAIN board.
2. Turn the POWER ON.

TEST MODE
terminal

1. Turn the POWER OFF.
2. Open the short-circuit to release test mode.

– 11 –

6. Adjust RV701 so that the oscilloscope waveform is as shown in

the figure below (eye pattern).
A good eye pattern means that the diamond shape (

◊

) in the center

of the waveform can be clearly distinguished.

7. Release test mode after adjustment is completed.

r

 RF signal reference waveform (eye pattern)

1.1 

±

 0.2V

VOLT/DIV : 0.2V
TIME/DIV : 500ns  

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

 

+

–

oscilloscope

(DC range)

TP (RFO)

TP (VC)

Adjustment Location : Main board (page 13)

A frequency responce analyzer is necessary in order to perform this
adjustment exactly.
However, this gain has a margin, so even if it is slightly off, there is
no problem. Therefore, do not perform this adjustment.
Focus/tracking gain determines the pick-up follow-up (vertical and
horizontal) relative to mechanical noise and mechanical shock when
the 2-axis device operate.
However, as these reciprocate, the adjustment is at the point where
both are satisfied.

r

 When gain is raised, the noise when the 2-axis device operates

increases.

r

 When gain is lowered, mechanical shock and skipping occurs

more easily.

r

 When gain adjustment is off, the symptoms below appear.

This adjustment is to be done when the optical pick-up block is re-
placed.

1. Connect the oscilloscope between TP (VC) and TP (TO) on main

board.

2. Put the set into test mode.
3. optical pick-up setting  to the center by + or = button push-

ing.

4. Insert disc (YEDS-18) and press ^ button.
5. Adjust RV703 so that the oscilloscope traveres waveform is sym-

metrical, as shown in the figure below.

6. Release test mode after adjustment is completed.

   

A          

0V

B

C

VOLT / DIV : 1V
TIME / DIV :1ms

A = B

C = 350mV 

±

 120mV

+

-

oscilloscope

(DC range)

TP (TO)

TP (VC)

Adjustment Location : Main board (page 13)

This adjustment is to be done when the optical pick-up block is re-
placed.

Adjustment procedure :
1. Connect oscilloscope to test point TP (VC) and TP (RFO) on main

board.

2. Put the set into test mode.
3. Optical pick-up setting to the center by + or = button push-

ing.

4. Insert disc (YEDS-18) and press CD PLAY ^ button.
5. Press the ^ button.  (Tracking servo ON)

– 12 –

5. Connect oscilloscope to TP(TO) and TP(VC) on MAIN board.
6. Adjust RV704 on digital board so that the waveform is as shown

in the figure below. (Tracking Gain Adjustment)

7. Release test mode after adjustment is completed.

0V

low tracking gain

high tracking gain
high fundamental wave
than for low gain

high focus gain

0V

0V

VOLT / DIV : 1V
TIME / DIV : 2ms

VOLT / DIV : 1V
TIME / DIV : 2ms

VOLT / DIV : 1V
TIME / DIV : 2ms

r

 

Incorrect Examples (fundamental wave appears)

+

–

oscillcope

(DC range)

TP (TO)

TP (FO)

TP (VC)

Adjustment Location : Main board (page 13)

r 

The time until music starts becomes

 longer for STOP 

→ 

^

 

button or 

automatic selection.
( =, + buttons pressed.)
(Normally takes about 2 seconds.)

r  

Music does not start and disc

 continues to rotate for STOP 

→ 

^

 

button or automatic selection.

(  =, + buttons pressed.)

r    

Sound is interrupted during PLAY. 

Or time counter display stops
 progressing.

r   

More noise during 2-axis device

 operation.

Symptoms

Gain

Focus

Tracking

low   

  low or high

–

           low

–

           low

high

            high

The following is a simple adjustment method.

Since exact adjustment cannot be performed, remember the
positions of the controls before performing the adjustment.If
the positions after the primary adjustment are only a little
different, return the controls to the original position.

Procedure :
1. Keep the set horizontal.

If the set is not horizontal, this adjustment cannot be performed
due to the gravity against the 2-axis device.

2. Insert disc (YEDS-18) and press ^ button.
3. Connect oscilloscope to TP(FO) and TP (VC) on MAIN board.
4. Adjustment RV702 on MAIN board so that the waveform is as

shown in the figure below. (focus gain adjustment)

100mV

0V

200mV

low focus gain

high focus gain

0V

75mV

0V

VOLT / DIV : 100mV
TIME / DIV : 2ms

VOLT / DIV : 100mV
TIME / DIV : 2ms

VOLT / DIV : 100mV
TIME / DIV : 2ms

r

 

Incorrect Examples (DC level changes more than on adjusted

   waveform)