DOWNLOAD Sony CFD-Z125 / CFD-Z135 Service Manual ↓ Size: 1.31 MB | Pages: 41 in PDF or view online for FREE

— 17 —

3. Phase Check

Mode: playback

4. After the adjustment, lock the screws with locking compound.

V

H

oscilloscope

SPEAKER terminal (JK302)

test tape
P-4-A063
(6.3kHz, –10dB)

set

L-CH

L-CH
32 

Ω

32 

Ω

R-CH

R-CH

screen pattern

in phase

45

°

90

°

135

°

180

°

good

wrong

Deck

screwdriver

Procedure :
Mode : Playback

Adjustment Value :  normal tape speed (3,000Hz)

Frequency difference between the beginning and the end of the
tape should be within 3% (90Hz).

Adjustment Location : Motor, M601

Digital frequency counter

2,985 – 3,015Hz

Speed checker

–3.0 to 3.0%

3.2 

Ω

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

set

speed checker
LFM-30 or
digital frequency
counter

SPEAKER Terminal
(JK302)

+

–

Tape speed adjustment
control inside motor, M601

— 18 —

• Repeat the procedures in each adjustment several times, and the

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

AM IF ADJUSTMENT

Adjust for a maximum reading on level meter.

T1

455kHz

Put the lead-wire
antenna close to
the set.

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

AM RF SSG

0.01

µ

F

FM RF SSG

FM telescopic
antenna terminal

75kHz frequency deviation
by 1 kHz signal.
output level : as low as possible

set

3.2 

Ω

set

+

–

level meter

SPEAKER terminal (JK302)

AM FREQUENCY COVERAGE ADJUSTMENT

Adjust for a maximum reading on level meter.

L4

520kHz

CT4

1,780kHz

AM TRACKING ADJUSTMENT

Adjust for a maximum reading on level meter.

L3

600kHz

CT3

1,400kHz

FM FREQUENCY COVERAGE ADJUSTMENT

Adjust for a maximum reading on level meter.

L2

97.5MHz

CT2

108.5MHz

FM TRACKING ADJUSTMENT

Adjust for a maximum reading on level meter.

L1

90MHz

CT1

106MHz

Adjustment Locastion: MAIN board (See page 19.)

1. Connect the frequency counter to pin 

4 of IC1 as shown the

figure below.

2. Tune the set to 98MHz.
3. Adjust RV1 for 75.95kHz to 76.05kHz reading on the frequency

counter.

Adjustment Locastion: MAIN board (See page 19.)

0.01

µ

F

FM RF SSG

FM telescopic
antenna terminal

Carrier frequency : 98MHz
Modulation           : no modulation
Output level         : 0.1V (100dB)

set

IC1 pin 

4

MAIN board

1

µ

F

frequency counter

— 19 —

L4

CT4

CT3

AM Tracking Adjustment

CT1

L1

T1
AM IF Adjustment

16

15

1 4

IC1

L2

CT2

FM Frequency Coverage

Adjustment

RV1 VCO Adjustment

FM Tracking
Adjustment

L3

AM Tracking Adjustment

AM Frequency Coverage

Adjustment

— 20 —

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, Parts No. 3-702-101-01) only when
so indicated.

1.

Short-circuit the pin 

#∞ and GND of IC801 on the CD

DECODER board as shown.

2.

Insert the AC plug cord into the power outlet and turned ON
the power switch.

3.

The LCD display change in 5 ways, and stop when they all
light up. (The unit sets in the test mode after the above steps.)

4.

Remove the short-circuit connected in step 1.

1.

Turn OFF the power switch.

2.

The set thus becomes available for normal operation.

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

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.

± : Optical pick-up moves to the outer circumference.
≠ : Optical pick-up moves to the inner circumference.

1.

Press the CD ± button. (Focus search operation is performed
continuously.)

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
the π button again longer.

GND

Jumper

IC801
pin-35