HCD-EH15
12
Adjustment Location:
L851
AM Tracking
Adjustment
L805
FM VT
Voltage
Adjustment
L804
FM Tracking
Adjustment
L806
FM Detector
Adjustment
L852
AM VT
Voltage
Adjustment
– MAIN Board (Component Side) –
JW403
(TUNER OUT L-ch)
JW402
(TUNER OUT R-ch)
JW148
(GND)
JW821
(VT)
CNP802
JW805
(GND)
– MAIN Board (Conductor Side) –
3
1
FM TUNE LEVEL CHECK
signal
generator
set
Procedure:
1. Turn on the set.
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 set.
You cannot use video cable for checking.
Use signal generator whose output impedance is 75 ohm.
3. Set to FM tuner function and tune A, B and C signals.
4. Con
fi
rm “TUNED” is lit on the display for A, B and C sig-
nals.
When the selected station signal is received in good condition,
“TUNED” is displayed.
CD SECTION
Note:
1. CD Block is basically constructed to operate without adjust-
ment.
2. Use YEDS-18 disc (3-702-101-01) unless otherwise indicat-
ed.
3. Use an oscilloscope with more than 10 M
Ω
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 fol-
lowing checks.
5. Check the focus bias check when optical pick-up block is re-
placed.
FOCUS BIAS CHECK
+
–
CD board
TP122 (RFEQO)
TP124 (VC)
oscilloscope
(DC range)
Procedure:
1. Connect oscilloscope to TP122 (RFEQO) and TP124 (VC) on
the CD board.
2. Press the [
?
/
1
] button to turn the power on.
3. Set the disc (YEDS-18) and press the [CD
u
] button to play-
back.
4. 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:
1.2 ± 0.3 Vp-p
Checking Location:
TP124
(VC)
– CD Board (Conductor Side) –
TP122
(RFEQO)
IC101