Sony MHC-V41D, Руководство по обслуживанию

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MHC-V41D
37
SECTION 4
ELECTRICAL CHECKS
TUNER SECTION 0 dB = 1

V
FM AUTO STOP CHECK
signal
generator
unit
Procedure:
1. Press the [
1
] button to turn the power on.
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 select the “TUNER FM”
function and scan the input FM signal with automatic scan-
ning.
4. Con fi 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.
DVD/CD SECTION
Note:
1. DVD/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 M

impedance.
4. Clean the object lens by an applicator with neutral detergent when the
signal level is low than speci fi ed value with the following check.
RF SIGNAL CHECK
+
–
MOTHER board
CN302 pin 17 (RF)
CN302 pin 1 (GND)
oscilloscope
(DC range)
Procedure:
1. Connect the oscilloscope to CN302 pin 17 (RF) and CN302
pin 1 (GND) on the MOTHER board.
2. Press the [
1
] button to turn the power on.
3. Press the [FUNCTION] button to select the “DVD/CD” func-
tion.
4. Press the [
Z
] button to open the disc tray and set the disc
(YEDS-18).
5. Press the [
Z
] button to close the disc tray.
6. Press the [
N
] button to playback.
7. Con fi 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: 1.0 ± 0.25 Vp-p
Connection Location:
pin 17 (RF)
pin 1 (GND)
CN302
IC109
IC2001
– MOTHER Board (Side A) –