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Model
CFD-G55
Pages
52
Size
9.5 MB
Type
PDF
Document
Service Manual
Brand
Device
Audio
File
cfd-g55.pdf
Date
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13
CFD-G55
4-1. Mechanical Adjustments
PRECAUTION
1.
Clean the following parts with a denatured-alcohol-moistened
swab :
record/playback head
pinch roller
erase head
rubber belts
capstan
2.
Demagnetize the record/playback head with a head demagne-
tizer. (Do not bring the head demagnetizer close to the erase
head.)
3.
Do not use a magnetized screwdriver for the adjustments.
4.
The adjustments should be performed with the rated power
supply voltage (12V) unless otherwise noted.
Torque Measurement
Torque
Torque Meter
Meter Reading
1.77 – 5.88 mN•m
Forward
CQ-102C
(18 – 60 g•cm)
(0.25 – 0.83 oz•inch)
Forward
0.1 – 0.49 mN•m
Back Tension
CQ-102C
(1.0 – 5.0 g•cm)
(0.014 – 0.069 oz•inch)
4.42 – 9.31 mN•m
Fast Forward
CQ-201B
(45 – 95 g•cm)
(0.62 – 1.32 oz•inch)
4.42 – 9.31 mN•m
Rewind
CQ-201B
(45 – 95 g•cm)
(0.62 – 1.32 oz•inch)
Tape Tension  Measurement
Torque Meter
Meter Reading
CQ-403A
more than 60g
(more than 2.12 oz)
SECTION 4
ADJUSTMENTS
4-2. Electrical Adjustments
 TAPE SECTION
Standard Output Level
Output terminal
HP OUT
load impedance
32 
Ω
output signal level
0.25V (–10dB)
Test Tape
Type
Signal
Used for
WS-48A
3kHz, 0dB
Tape Speed Adjustment
Tape Speed Adjustment
Procedure :
Mode : Playback
Adjustment so than the value on the digital frequency counter is
3,000 Hz.
Adjustment Value : 3,000Hz
Standard Value : 2,940 - 3,060Hz
Frequency difference between the beginning and the end of the tape
should be within 1.5% (45Hz).
set
test tape
WS-48A
(3kHz, 0dB)
32
Ω
digital frequency
counter
J391 
(
 
i
 
)
Tape speed adjustment 
control inside motor
 0dB = 0.775V
Adjustment Location : Mechanism deck
14
CFD-G55
• Repeat the procedures in each adjustment several times, and the
frequency coverage and tracking adjustments should be finally
done by the trimmer capacitors.
 TUNER SECTION
 AM Section
Function switch : AM
 FM Section
Function switch : FM
• Connecting Level Meter (FM and AM)
• Connecting Digital Voltmeter (FM and AM)
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.
FM RF signal
generator
33.75kHz frequency deviation by 
1kHz signal.
Output level : as low as possible
telescopic
antenna
terminal
0.01
µ
F
 0dB = 1 
µV
digital
voltmeter
100 k
Ω
TP  CV
J391 
(
 
i
 
)
set
32 
Ω
level meter
(range: 0.5–5 V ac)
Ver 1.1  2002.05
AM IF ADJUSTMENT
Adjust for a maximum reading on level meter.
T1
450 kHz
(    ): 9 kHz step (MY, SP, EA)
<  >: 10 kHz step (MY, SP, EA)
no mark: Others
AM FREQUENCY COVERAGE ADJUSTMENT
Frequency Display
530 kHz
1,710 kHz
(531 kHz)
(1,611 kHz)
<530 kHz>
<1,610 kHz>
Reading on Digital voltmeter
1.0 
± 0.1 V
5.3 
± 0.8V
(4.8 
± 0.8V)
<4.8
± 0.8V>
Adjustment Part
 L 4
confirmation
<  >: 9 kHz step (MY, SP, EA)
no mark: Others
AM TRACKING ADJUSTMENT
Adjust for a maximum reading on level meter.
L3
CT3
620 kHz 
<
621
kHz>
1,400 kHz <1,404 kHz>
FM IF ADJUSTMENT
Adjust for a maximum reading on level meter.
T2
10.7 MHz
FM FREQUENCY COVERAGE ADJUSTMENT
Frequency Display
87.5 MHz
108 MHz
Reading on Digital voltmeter
1.3 
± 0.4 V
3.0 
± 0.3 V
Adjustment Part
confirmation
L2
FM TRACKING ADJUSTMENT
Adjust for a maximum reading on level meter.
L1
CT1
87.5 MHz
108 MHz
Abbreviation
MY : Malaysia model.
SP
: Singapore model.
EA
: Saudi Arabia model.
Adjustment Location : TUNER board (See page 16)
15
CFD-G55
Focus Bias Check
1.
Connect an oscilloscope between TP  RF  and TP  VREF   on
CD board.
2.
Insert the test disc (YEDS-18).
3.
Set the CD test mode.
4.
Press the  u  button three times (LPC ON).
5.
Confirm 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.
6.
Press the  u  button.(LPC OFF)
7.
Perform confirmation in step 4 again.
• RF Signal Reference Waveform (eye pattern)
RF level
0.85 
±
 0.2 Vp-p (LPC ON)
0.95 
±
 0.4 Vp-p (LPC OFF)
VOLT/DIV : 200mV
TIME/DIV : 500 ns
 CD SECTION
CD Test  Mode
• How to put the set into CD test mode
1.
Press the  POWER  button to turn the power on.
2.
Insert the test disc (YEDS-18). (Part No. : 3-702-101-01)
(Function is set to CD.)
3.
Set the CD test mode by momentary shorting both sides of
TEST- 1 on MAIN board.
4.
Press the  x  button two times. The set is set to the CD test
mode.
(The message 
80 is displayed.)
• How to release the CD test mode
Turn the power off.
[MAIN BOARD] (Conductor side)
Traverse Waveform Check
1.
Connect an oscilloscope between TP  TE  and TP  VREF  on
CD board.
2.
Set the CD test mode.
3.
Press the  u  botton to play the test disc (YEDS-18).
4.
Confirm that the center of the traverse waveform will be at 0V.
5.
Confirm that the peak-to-peak voltage value of the traverse
waveform meets the specification.
6.
Release the CD test mode.
• Traverse waveform
A (DC voltage)
symmetry
0V
A = 0 
±
 220 mV
B = 0.95 
±
 0.55 Vp-p
B
VOLT/DIV : 200mV
TIME/DIV : 1 ms
IC803
IC802
IC805
IC321
IC801
TEST-1
[CD BOARD] (Conductor side)
IC701
 TP  VREF
 TP  TE
 TP  RF
16
CFD-G55
Adjustment Location :
CT1: FM Tracking Adjustment
L1: FM Tracking Adjustment
L3: AM Tracking Adjustment
CT3: AM Tracking Adjustment
CNP1
L4: AM Frequency Coverage Adjustment 
T1: AM IF Adjustment 
T2: FM IF Adjustment 
L2: FM Frequency Coverage Adjustment 
[TUNER BOARD] (Component side)
IC1
IC2
TP  CV
AM/FM Frequency Coverage Adjustment
(Conductor side)
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