Electirical Check - Sony D-NF400 Service Manual

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3 7 6 3 1 5 1 5 0 ELECTRICAL CHECK
CD SECTION
The CD section adjustments are done automatically in this set.
In case of operation check, confirm that focus bias.
Precautions for Check
1. Perform check in the order given.
2. Use YEDS-18 disc (Part No.: 3-702-101-01) unless otherwise
indicated.
3. Power supply voltage requirement: DC4.5 V in DC IN jack.
(J401)
HOLD switch : OFF
Connecting and Checking Location:
– MAIN Board (Conductor Side) –
TP601
(RF)
T E
L 1 3 9 4 2 2 9 6 5 1 3
TP498
(MAIN_GND)
w w w
.
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SECTION 5
Focus Bias Check
Condition:
• Hold the set in horizontal state.
Connection:
oscilloscope
(AC range)
MAIN board
2 k Ω
TP601 (RF)
+
TP498 (MAIN_GND)
–
Procedure:
1. Connect the oscilloscope to the test points TP601 (RF) and
TP498 (GND) on the MAIN board.
2. Set a disc. (YEDS-18)
3. Push the N X button.
4. Check the oscilloscope waveform is as shown below.
A good eye pattern means that the diamond shape (◊) in the
center of the waveform can be clearly distinguished.
RF Signal reference Waveform (Eye Pattern)
VOLT/DIV : 100 mV (With the 10:1 probe in use)
TIME/DIV : 500 ns
To watch the eye pattern, set the oscilloscope to AC range and
increase the vertical sensitivity of the oscilloscope for easy watch-
ing.
5. Stop revolving of the disc motor by pressing the
x a o
y
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8
TUNER SECTION
[AM]
Setting:
Band switch : AM
Put the lead-wire
AM RF signal
antenna close to
generator
the set.
30% amplitude
modulation by
400 Hz signal
Output level: as low as possible
[FM]
Setting:
Band switch : FM
FM RF signal
MAIN board
generator
TP (FM ANT)
0.01 µ F
22.5 kHz frequency
deviation by 400 Hz
signal
Output level: as low as possible
RF level
0.45 to 0.65 Vp-p
MAIN board
Q Q
3 7 6 3 1
TP8 (VT)
TP498 (MAIN_GND)
• Repeat the procedures in each adjustment several times, and the
frequency coverage and tracking adjustments should be finally
done by the trimmer capacitors.
button.
x
– MAIN Board (Component Side) –
L3 AM Tracking
CT3 Adjustment
u 1 6 3
.
11 11
2 4
9 9 8
( ): AEP, UK, East European, E, Australian Models
0 dB=1 µV
AM FREQUENCY COVERAGE CONFIRMATION
Adjustment Part Frequency Display Reading on Digital Voltmeter
Confirmation
Confirmation
level meter
Adjust for a maximum reading on level meter
32 Ω
L3
+
set
– CT3
MAIN board
i jack (J301)
( ): AEP, UK, East European, E, Australian Models
FM FREQUENCY COVERAGE CONFIRMATION
Adjustment Part Frequency Display Reading on Digital Voltmeter
Confirmation
Adjust for a maximum reading on level meter
level meter
L1
32 Ω
+
set
–
Adjust for a maximum reading on level meter
MAIN board
L5
i jack (J301)
digital voltmeter
100 k Ω
5 1 5 0 8 9 2 4
– MAIN Board (Conductor Side) –
m
c o
D-NF400/NF401
2
9 9
530 (531) kHz 1.0 ± 0.5 V
7.3 ± 1.0 (6.8 ± 1.0) V
1,710 (1,602) kHz
AM TRACKING ADJUSTMENT
620 kHz
1400 kHz
5.1 ± 0.5 (8.7 ± 0.5) V
87.5 (108.0) MHz
FM TRACKING ADJUSTMENT
98.0 MHz
TV TRACKING ADJUSTMENT
ch10/97.75 MHz
(D-NF400: US, Canadian models only)
9 8 2 9 9
TP8
(VT)
L1 FM Tracking
Adjustment
L5 TV Tracking
Adjustment
D-NF400: US,
TP428
Canadian models
(MAIN_GND)