Electrical Adjustments - Sony HCD-EC69i Service Manual

ELECTRICAL ADJUSTMENTS

CD SECTION
Note:
1. CD Block is basically constructed to operate without adjustment.
2. Use YEDS-18 disc (Part No. 3-702-101-01) unless otherwise indicat-
ed.
3. Use an oscilloscope with more than 10 MΩ impedance.
4. Clean the object lens by an applicator with neutral detergent when the
signal level is low than specifi ed value with the following checks.
5. Check the focus bias check when optical pick-up block is replaced.
FOCUS BIAS CHECK
oscilloscope
(DC range)
CD board
TP121 (RFI)
+
TP124 (VC)
–
Procedure:
1. Connect the oscilloscope to TP121 (RFI) and TP124 (VC) on
the CD board.
2. Press the [ ] button to turn the power on, and press the
?/1
[FUNCTION] button to select CD function.
3. Set disc (YEDS-18) and press the [u] button to playback.
4. Confi rm that oscilloscope waveform is as shown in the fi gure
below (eye pattern).
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
level:
1.2 ± 0.3 Vp-p
Checking Location:
– CD Board (Conductor Side) –
TP124
(VC)
TP121
(RFI)
IC101
HCD-EC69i/EC79i/EC99i
SECTION 5
0 dB = 1 μV
TUNER SECTION
[AM]
Setting:
FUNCTION: AM
60 cm
loop antenna A loop antenna B
AM RF signal
generator
set
30% amplitude
modulation by
JACK board
400 Hz signal
MAIN board
PHONES jack (J492)
Output level: 54 dBuV CN801 pin
[FM]
Setting:
FUNCTION: FM
FM RF signal
generator
MAIN board
CN801 pin
0.01 F
set
JACK board
75 kHz frequency
MAIN board
PHONES jack (J492)
deviation by 1 kHz
CN801 pin
signal
Output level: as low as possible
(8 dBuV)
digital voltmeter
MAIN board
100 k Ω
IC801 pin (TUNER VT)
•
Repeat the procedures in each adjustment several times.
AM FREQUENCY COVERAGE CONFIRMATION
(US, Canadian and Australian models)
Frequency Display Reading on Digital Voltmeter
530 kHz 1.45 ± 0.3 V
1,710 kHz
AM FREQUENCY COVERAGE CONFIRMATION
(UK model)
Frequency Display Reading on Digital Voltmeter
531 kHz 1.45 ± 0.3 V
1,602 kHz
AM TRACKING ADJUSTMENT
(US, Canadian and Australian models)
Adjust for a maximum reading on level meter
L805
AM TRACKING ADJUSTMENT (UK model)
Adjust for a maximum reading on level meter
L805
FM FREQUENCY COVERAGE ADJUSTMENT
Adjustment Part Frequency Display
L803
Confi rmation
FM TRACKING ADJUSTMENT
Adjust for a minimum reading on level meter
level meter
L804
32 Ω
+
– FM DETECTOR ADJUSTMENT
Setting:
FUNCTION: FM
FM RF signal
generator
level meter
Carrier frequency: 98 MHz
32 Ω
Modulation:
deviation by FM 75 kHz
+
Output level: 60 dBuV
–
1. Turn the set to 98 MHz.
2. Adjust L802 so that modulation distortion may become the
best in the vicinity of the maximum value where the tuner out
level becomes –15 dBuV or more.
FM AUTO STOP CHECK
SET
Procedure :
1. Turn the power on.
7.7 ± 0.5 V
2. Input the following signal from Signal Generator to FM an-
tenna input directly.
Carrier frequency : A = 87.5 MHz, B = 98 MHz, C = 108 MHz
Deviation : 75 kHz
Modulation : 1 kHz
ANT input : 35 dBu (EMF)
7.2 ± 0.5 V
Note: Please use 75 ohm "coaxial cable" to connect SG and the set. You
cannot use video cable for checking.
Please use SG whose output impedance is 75 ohm.
3. Set to FM tuner function and scan the input FM signal with
automatic scanning.
530 kHz
4. Confi rm that input Frequency of A, B and C detected and auto-
matic scanning stops.
The stop of automatic scanning means "The station signal is re-
ceived in good condition".
531 kHz
23 23
Adjustment Location and Connecting Points:
Reading on Digital
– MAIN Board (Component Side) –
Voltmeter
87.5 kHz 1.75 ± 0.1 V
108 kHz 6.2 ± 0.5 V
98 MHz
MAIN board
IC801 pin
(TUNER OUT L-ch)
MAIN board
L804
CN801 pin
level meter FM Tracking
Adjustment
+
set
–
MAIN board
MAIN board JW801 (TUNER-GND)
CN801 pin
– MAIN Board (Conductor Side) –
3
CN801
36
1
1
IC801
generator
IC801 pin
(TUNER OUT L-ch)
+
75 Ω
HCD-EC69i/EC79i/EC99i
Ver. 1.1
L802
FM Detector
Adjustment
L803
FM Frequency
Coverage
Adjustment
L805
AM Tracking
Adjustment
IC801 pin
(TUNER VT)
19
18
JW801
(TUNER-GND)