Sony CMT-GB3 / HCD-GB3 Service Manual ▷ View online
17
HCD-GB3
Checking Location:
+
–
–
BD83S board
TP (RFACI)
TP (VC)
TP (VC)
oscilloscope
(DC range)
Procedure :
1. Connect oscilloscope to TP (RFACI) and TP (VC) on the
BD83S board.
2. Press the
I/
1 button to turn the power ON, and press
the Z (CD) button to open the CD disc tray.
3. Set disc (YEDS-18) on the tray and press the
CD
7 button
to playback.
4. Confirm that oscilloscope waveform is as shown in the figure
below. (eye pattern)
A good eye pattern means that the diamond shape (
A good eye pattern means that the diamond shape (
◊) in the
center of the waveform can be clearly distinguished.
VOLT/DIV: 200 mV
TIME/DIV: 500 ns
TIME/DIV: 500 ns
level:
0.9
0.9
±
0.4 Vp-p
TP
(VC)
TP
(RFACI)
IC201
– BD83S Board (SIDE B) –
CD SECTION
Note:
1.
CD Block is basically constructed to operate without adjustment.
2.
Use YEDS-18 disc (3-702-101-01) unless otherwise indicated.
3.
Use an oscilloscope with more than 10 M
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.
5.
Check the focus bias check when optical pick-up block is replaced.
FOCUS BIAS CHECK
Adjustment Location: Record/Playback/Erase Head
18
HCD-GB3
TUNER SECTION
0 dB=1
µ
V
[AM]
Setting:
FUNCTION: TUNER
TUNER/BAND button: AM
FUNCTION: TUNER
TUNER/BAND button: AM
[FM]
Setting:
FUNCTION: TUNER
TUNER/BAND button: FM
FUNCTION: TUNER
TUNER/BAND button: FM
•
Repeat the procedures in each adjustment several times.
AM RF signal
generator
30% amplitude
modulation by
400 Hz signal
Output level: 54 dBuV
60 cm
set
loop antenna A loop antenna B
+
–
–
level meter
32
Ω
JACK board
PHONES jack (J102)
PHONES jack (J102)
FM RF signal
generator
75kHz frequency
deviation by 1K Hz
signal
Output level: as low as possible
(8dBuV)
deviation by 1K Hz
signal
Output level: as low as possible
(8dBuV)
+
–
–
level meter
set
32
Ω
0.01
µ
F
JACK board
PHONES jack (J102)
PHONES jack (J102)
MAIN board
ANTENNA
CNP802 pin
1
MAIN board
ANTENNA
CNP802 pin
2
digital voltmeter
100 k
Ω
MAIN board
TP (TUNER VT)
AM FREQUENCY COVERAGE ADJUSTMENT
Adjustment Part
Frequency Display
Reading on Digital Voltmeter
L852
530 kHz
1.5
± 0.1 V
Confirmation
1,710 kHz
8
± 0.5 V
AM TRACKING ADJUSTMENT
Adjust for a maximum reading on level meter
L851
530 kHz
FM FREQUENCY COVERAGE ADJUSTMENT
Adjustment Part
Frequency Display
Reading on Digital Voltmeter
L805
87.5 MHz
1.75
± 0.1 V
Confirmation
108 MHz
6.2
± 0.5 V
FM TRACKING ADJUSTMENT
Adjust for a maximum reading on level meter
L804
98 MHz
Adjustment Location: MAIN board (See page 19).
[FM DETECTOR ADJUSTMENT]
Setting:
FUNCTION: TUNER
TUNER/BAND button: FM
FUNCTION: TUNER
TUNER/BAND button: FM
1. Tune the set to 98 MHz.
2. Adjust L806 so that modulation distortion may become the
2. Adjust L806 so that modulation distortion may become the
best in the vicinity of the maximum value where the tuner out
level becomes –15dBuV or more.
level becomes –15dBuV or more.
FM RF signal
generator
Carrier frequency: 98MHz
Modulation:
deviation by FM 75 kHz
Output level: 60 dBuV
Modulation:
deviation by FM 75 kHz
Output level: 60 dBuV
+
–
–
level meter
MAIN board
TP (TUNER GND)
TP (TUNER GND)
MAIN board
IC801 pin
IC801 pin
qs
(TUNER OUT L-ch)
set
MAIN board
ANTENNA
CNP802 pin
ANTENNA
CNP802 pin
2
MAIN board
ANTENNA
CNP802 pin
ANTENNA
CNP802 pin
1
19
HCD-GB3
Adjustment Location and Connecting Points
L851
CNP802
L852
L804
L805
AM TRACKING
ADJUSTMENT
ADJUSTMENT
FM TRACKING
ADJUSTMENT
ADJUSTMENT
(TUNER GND)
(TUNER VT)
FM FREQUENCY
COVERRANGE
ADUJUSTMENT
COVERRANGE
ADUJUSTMENT
AM FREQUENCY
COVERRANGE
ADUJUSTMENT
COVERRANGE
ADUJUSTMENT
FM DETECTOR
ADUJUSTMENT
ADUJUSTMENT
– MAIN BOARD (Component side) –
– MAIN BOARD (Condutor side) –
L806
TP (TUNER VT)
TP (TUNER GND)
IC801 pin
qs
(TUNER OUT L-ch)
3
1
1
20
HCD-GB3
Note on Schematic Diagram:
• All capacitors are in
• All capacitors are in
µ
F unless otherwise noted. (p: pF)
50 WV or less are not indicated except for electrolytics and
tantalums.
tantalums.
• All resistors are in
Ω
and
1
/
4
W or less unless otherwise
specified.
•
f
: internal component.
•
2
: nonflammable resistor.
•
5
: fusible resistor.
•
C
: panel designation.
•
H
: adjustment for repair.
•
A
: B+ Line.
•
B
: B– Line.
• Voltages are taken with a VOM (Input impedance 10 M
Ω
).
Voltage variations may be noted due to normal production
tolerances.
tolerances.
• Waveforms are taken with a oscilloscope.
Voltage variations may be noted due to normal production
tolerances.
– BD83S BOARD –
No mark: CD PLAY
– Other Section –
No mark: FM
tolerances.
– BD83S BOARD –
No mark: CD PLAY
– Other Section –
No mark: FM
• Circled numbers refer to waveforms.
• Signal path.
F
: TUNER (FM)
f
: TUNER (AM)
J
: CD
d
: AUX
E
: PB (TAPE)
a
: REC (TAPE)
• Abbreviation
AR
: Argentine model
E2
: 120V AC area in E model
MX
: Mexican model
Note on Printed Wiring Boards:
•
•
X
: parts extracted from the component side.
•
Y
: parts extracted from the conductor side.
•
f
: internal component.
•
: Pattern from the side which enables seeing.
• Indication of transistor.
THIS NOTE IS COMMON FOR PRINTED WIRING BOARDS AND SCHEMATIC DIAGRAMS.
(In addition to this, the necessary note is printed in each block.)
(In addition to this, the necessary note is printed in each block.)
SECTION 7
DIAGRAMS
Note: The components identified by mark
0
or dotted
line with mark
0
are critical for safety.
Replace only with part number specified.
B
These are omitted.
C
E
Q
C
B
These are omitted.
E
Q
Click on the first or last page to see other CMT-GB3 / HCD-GB3 service manuals if exist.