Electrical Adjustments - Sony HCD-EC69 Service Manual

HCD-EC69/EC79/EC99
Ver. 1.2
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.
Checking Location:
– CD Board (Conductor Side) –
TP124
(VC)
TP121
(RFI)
IC101
18
SECTION 5

ELECTRICAL ADJUSTMENTS

Adjustment Location: MAIN board (See page 19)
[AM]
Setting:
FUNCTION: AM
Output level: 54 dBuV
[FM]
Setting:
FUNCTION: FM
VOLT/DIV: 200 mV
75 kHz frequency
TIME/DIV: 500 ns
deviation by 1 kHz
signal
Output level: as low as possible
level:
1.2 ± 0.3 Vp-p
IC801 pin
•
0 dB = 1 μV
TUNER SECTION
60 cm
loop antenna A loop antenna B
AM RF signal
generator
30% amplitude
modulation by
400 Hz signal
MAIN board
CN801 pin
FM RF signal
generator
MAIN board
CN801 pin
0.01 F
set
MAIN board
CN801 pin
(8 dBuV)
MAIN board
100 k Ω
(TUNER VT)
Repeat the procedures in each adjustment several times.
(
AM FREQUENCY COVERAGE CONFIRMATION
Frequency Display
530 kHz (531 kHz)
1,710 kHz (1,602 kHz)
(
AM TRACKING ADJUSTMENT
Adjust for a maximum reading on level meter
L805
FM FREQUENCY COVERAGE ADJUSTMENT
Adjustment Part Frequency Display
L803 87.5 kHz
Confi rmation 108 kHz
FM TRACKING ADJUSTMENT
Adjust for a minimum reading on level meter
L804
level meter
32 Ω
+
set
–
JACK board
PHONES jack (J492)
level meter
32 Ω
+
–
JACK board
PHONES jack (J492)
digital voltmeter
): EC69: AEP, Russian/EC79: AEP/
EC99: AEP and Russian models
Reading on Digital Voltmeter
1.45 ± 0.3 V
7.7 ± 0.5 V (7.2 ± 0.5 V)
): EC69: AEP, Russian/EC79: AEP/
EC99: AEP and Russian models
530 kHz (531 kHz)
Reading on Digital
Voltmeter
1.75 ± 0.1 V
6.2 ± 0.5 V
98 MHz