Sony HCD-G2500 / HCD-XB20 / HCD-XB22 / LBT-G2500 / LBT-XB20 / LBT-XB22 Service Manual ▷ View online
— 13 —
TUNER SECTION
0 dB=1µV
AM Tuning Voltage Adjustment
Procedure:
1.
1.
Set the reception frequency of the unit to 530 kHz.
2.
Adjust L105 for 1.2 ± 0.05 V reading on the DC voltmeter.
3.
Set the reception frequency of the unit to 1,710 kHz.
4.
Confirm that the voltage reading on the DC voltmeter is within
8.0 ± 0.5 V.
8.0 ± 0.5 V.
Adjustment Location: MAIN board (See page 14)
AM Tracking Adjustment
Procedure:
1.
1.
Tune the set to 600 kHz.
2.
Set the output of AM RF SSG so that the input level of the set
will become 60 dB (µV/m).
will become 60 dB (µV/m).
3.
Adjust L104 so that when the waveform on the oscilloscope is
maximum, no noise appears.
maximum, no noise appears.
4.
Tune the set to 1,400 kHz.
5.
Adjust TC102 so that when the waveform on the oscilloscope
is maximum, no noise appears.
is maximum, no noise appears.
• Repeat the procedures in each adjustment several times, and the
tracking adjustment should be finally done by the trimmer
capacitors.
capacitors.
Adjustment Location: MAIN board (See page 14)
FM Tuning Voltage Adjustment (US, Australian, Mexican model)
DC voltmeter
Procedure :
1.
1.
Set the reception frequency of the unit to 87.5 MHz.
2.
Adjust L103 for 1.2 ± 0.05V reading on the DC voltmeter.
3.
Set the reception frequency of the unit to 108 MHz.
4.
Confirm that the voltage reading on the DC voltmeter is within
7.8 ± 0.5V.
7.8 ± 0.5V.
Adjustment Location: MAIN board (See page 14)
TP1
+
IF
G
VT
Main board
DC voltmeter
Main board
–
F
G
VT
G
VT
TP1
+
–
AM RF SSG
loop antenna
set
loop antenna
(Supplied accessories)
(Supplied accessories)
60 cm
AM ANTENNA
terminal (TM1)
terminal (TM1)
30% amplitude
modulation by
400 Hz signal
modulation by
400 Hz signal
Field strength dB (
µ
V/m) =SSG output level dB (
µ
V/m) –26 dB.
— 14 —
FM Tuned Level Adjustment
set
Procedure:
1.
1.
Supply a 28 dB 98 MHz signal from the ANTENNA terminal.
2.
Tune the set to 98 MHz.
3.
Adjust SFR101 to the point (moment) when the TUNED
indicator will change from going off to going on.
indicator will change from going off to going on.
Adjustment Location: MAIN board
FM Tracking Adjustment
(US, Australian, Mexican model)
(US, Australian, Mexican model)
Procedure:
1.
Tune the set to 90 MHz.
2.
Adjust L102 so that when the waveform on the oscilloscope is
maximum, no noise appears.
maximum, no noise appears.
3.
Tune the set to 106 MHz.
4.
Adjust TC101 so that when the waveform on the oscilloscope
is maximum, no noise appears.
is maximum, no noise appears.
• Repeat the procedures in each adjustment several times, and the
tracking adjustment should be finally done by the trimmer
capacitors.
capacitors.
Adjustment Location: MAIN board
Adjustment Location
[MAIN BOARD] — Component side —
Carrier frequency : 90 MHz, 106 MHz
Modulation
Modulation
: AUDIO 1kHz, 75kHz deviation (100%)
Output level
: 20 dB (at 75
Ω
open)
FM RF SSG
Carrier frequency : 98 MHz
Modulation
Modulation
: AUDIO 1 kHz, 75 kHz
deviation (100%)
Output level
: 28 dB (at 75
Ω
open)
FM ANTENNA terminal
(JK101)
(JK101)
75
Ω
coaxial
FM ANTENNA terminal (JK101)
SPEAKER terminal (JK703)
FM RF SSG
set
oscilloscope
JK101
L105
TC102
L104
IC301
L102
L103
TC101
SFR101
IC103
(AM
Tracking)
Tracking)
(AM Tuning
Voltage)
Voltage)
(FM Tuning
Voltage)
Voltage)
(FM
Tracking)
Tracking)
(FM Tuned Level)
SFR809
(Tape speed)
(Tape speed)
— 15 —
CD SECTION
Note:
1.
CD Block is basically constructed to operate without
adjustment. Therefore, check each item in order given.
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.
when the signal level is low than specified value with the
following checks.
5.
Adjust the focus bias adjustment when optical block is replaced.
Focus Bias Adjustment
RF Level Check
Procedure :
1.
1.
Connect oscilloscope to test point TP01 on CD DECODER
board.
board.
2.
Turned Power switch on.
3.
Put disc (YEDS-18) in and playback.
4.
Confirm that oscilloscope waveform is clear and check RF
signal level is correct or not.
signal level is correct or not.
Note: Clear RF signal waveform means that the shape “
◊
” can be
clearly distinguished at the center of the waveform.
oscilloscope
level: 1.0 Vp-p
VOLT/DIV: 200 mV
TIME/DIV: 500 nS
TIME/DIV: 500 nS
+0.3
–0.2
–0.2
Adjustment Location: CD DECODER board
Procedure:
1.
1.
Connect DC voltmeter to test point TP02 on CD DECODER
board.
board.
2.
Turned Power switch on.
3.
Put disc (YEDS-18) in and stop.
4.
Adjust VR01 so that the DC voltmeter reading is 0 ± 20 mV.
Adjustment Location: CD DECODER board
Focus Gain Adjustment (VR02)
This gain has a margin, so even if it is slightly off.
There is no problem.
Therefore, do not perform this adjustment.
Please note that it should be fixed to mechanical center position
when you moved and do not know original position.
There is no problem.
Therefore, do not perform this adjustment.
Please note that it should be fixed to mechanical center position
when you moved and do not know original position.
Adjustment Location
[CD DECODER BOARD] — Component side —
CD DECODER
board
board
TP02
FEO
VC
DC voltmeter
+
–
CD DECODER
board
board
RF
VC
VC
TP01
VR01
(Focus Bias)
(Focus Bias)
VR02
(Focus Gain)
(Focus Gain)
IC01
TP01
TP02
— 16 —
SECTION 5
DIAGRAMS
5-1. CIRCUIT BOARDS LOCATION
MAIN board
LED board
DISC board
DOOR SW board
AMP board
POWER SELECT board
POWER SUPPLY
board
board
JOG board
PLAY SW board
VR board
FRONT board
MOTOR board
CONNECTOR board
CD DECODER board
MOTOR (6P)(C) board
DISC NO LED board
TABLE SENSOR board
R/P SWITCH board
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