Electrical Checks - Sony CMT-BT60 Service Manual

DISC SLOT LOCK MODE
It can be unable to take sample disc out of disc slot in the shop.
Procedure:
1. Press the [ / ] button to turn the power on.
? 1
2. Press the [FUNCTION] button to turn the CD function.
3. Insert a disc in the unit.
4. Press two buttons of the [ ] and [ ] simultaneously for fi ve
x Z
seconds.
5. The message "LOCKED" is displayed on the liquid crystal
display and the disc slot is locked.
(Even if pressing the [ ] button, the message "LOCKED"
Z
is displayed on the liquid crystal display and the disc slot is
locked)
Releasing method:
1. Press two buttons of the [ ] and [ ] simultaneously for fi ve
x Z
seconds.
2. The message "UNLOCKED" is displayed on the liquid crystal
display and the disc slot is unlocked.
AM STEP CHANGE (Except AEP and UK models)
It can change AM step interval into 9 kHz or 10 kHz.
Procedure:
1. Press the [ ] button to turn the power on.
?/1
2. Press the [FUNCTION] button to turn the AM function.
3. Press the [ ] button to turn the power off.
?/1
4. Press two buttons of the [FUNCTION] and [
ously.
5. The message "STEP 9" or "STEP 10" is displayed on the liq-
uid crystal display, and AM step interval changed.
CHECK VERSION DISPLAY
It can confi rm the MC, CD and NW version.
Procedure:
1. Press the [ ] button to turn the power on.
?/1
2. Press two buttons of the [ ] and [BASS BOOST] simultane-
x
ously for three seconds.
3. It enters the check version display mode, the MC version is
displayed on the liquid crystal display.
4. Each time [ TUNE +] button is pressed, the display chang-
>
es CD version and NW version (CMT-BT80W/BT80WB only)
this order, and release from check version display mode.
CMT-BT60/BT60B/BT80W/BT80WB
] simultane-
?/1
TUNER SECTION 0 dB = 1 V
FM TUNE LEVEL CHECK
signal
generator
unit
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 tune A, B and C signals.
4. Confi rm "TUNED" is lit on the display for A, B and C signals.
When the selected station signal is received in good condition,
"TUNED" is displayed.
Connection Location:
– MAIN Board (Side A) –
CL576
(RF)
CL573
(GND)
29 29
CMT-BT60/BT60B/BT80W/BT80WB
SECTION 4

ELECTRICAL CHECKS

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 M 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.
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. Insert the disc (HLX-A1) in the unit and press the [
to playback.
5. 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)
+
–
] button
u
VOLT/DIV: 200 mV
TIME/DIV: 500 ns
level: 1.05 ± 0.45 Vp-p