Electrical Checks - Sony HCD-SBT100 Service Manual

0 dB = 1 μV
TUNER SECTION
FM AUTO STOP CHECK
signal
generator
Procedure:
1. Press the [ / ] button to turn the power on.
? 1
2. Input the following signal from signal generator to FM antenna
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)
Note: Use 75 ohm coaxial cable to connect signal generator and the unit.
You cannot use video cable for checking.
Use signal generator whose output impedance is 75 ohm.
3. Press the [FUNCTION] button to turn the FM tuner function
and scan the input FM signal with automatic scanning.
4. Confi rm that input frequency of A, B and C detected and auto-
matic scanning stops.
When the station signal is received in good condition, automatic
scanning stops.
Connection Location:
– MAIN Board (Component Side) –
HCD-SBT100/SBT100B/SBT300W/SBT300WB
SECTION 4

ELECTRICAL CHECKS

unit
CD SECTION
Note:
1. CD block is basically constructed to operate without adjustment.
2. Use HLX-A1 disc (Part No. J-2501-307-A) 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 check.
RF SIGNAL CHECK
MAIN board
CL576 (RF)
CL573 (GND)
Procedure:
1. Connect the oscilloscope to CL576 (RF) and CL573 (GND) on
the MAIN board.
2. Press the [ / ] button to turn the power on.
? 1
3. Press the [FUNCTION] button to turn the CD function.
4. Press the [ ] button to open the disc tray and set the disc
Z
(HLX-A1).
5. Press the [ ] button to close the disc tray.
Z
6. Press the [ ] button to playback.
u
7. 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.
oscilloscope
(DC range)
+
–
VOLT/DIV: 200 mV
TIME/DIV: 500 ns
level: 1.05 ± 0.45 Vp-p
CL573
(GND)
CL576
(RF)
25