Sony DHC-EX880MD / DHC-MD717 / ST-EX880 / ST-MS717 Service Manual ▷ View online
– 5 –
MAIN BOARD
Note:
Follow the disassembly procedure in the numerical order given.
SECTION 3
DISASSEMBLY
3
case
0
three screws
(BVTP3
(BVTP3
×
10)
1
two screws
(case3 TP2)
(case3 TP2)
4
flat type wire (19 core)
(CN102)
(CN102)
!¡
claw
7
two claws
6
two screws
(BVTT3
(BVTT3
×
6)
7
claw
8
front panel ass’y
5
connector
(CN104)
(CN104)
!¡
claw
!™
MAIN board
9
two screws
(BVTP3
(BVTP3
×
8)
1
two screws
(case3 TP2)
(case3 TP2)
2
screw
(BVTT3
(BVTT3
×
6)
– 6 –
0 dB=1 µV
Note:
As a front-end (FE1) is difficult to repair if faulty, replace it with
new one.
new one.
AM Section Adjustment
Setting:
AM Tuned Level Adjustment
Band: AM or MW
Procedure:
1. Set the output of SSG so that the input level of the set be-
Procedure:
1. Set the output of SSG so that the input level of the set be-
comes 55 dBµ/m.
2. Tune the set to 999 kHz or 1,000 kHz.
3. Adjust RV1 to the point (moment) when the TUNED indica-
3. Adjust RV1 to the point (moment) when the TUNED indica-
tor will change from going off to going on.
Adjustment Location : MAIN board
FM Section Adjustment
Note:
This adjustment should be performed after the AM Tuned Level
Adjustment due to the same adjustment element.
Setting:
FM Tuned Level Adjustment
Band: FM
Procedure:
1. Supply a 26 dBµ 98 MHz signal from the ANTENNA termi-
Procedure:
1. Supply a 26 dBµ 98 MHz signal from the ANTENNA termi-
nal.
2. Tune the set to 98 MHz.
3. If the TUNED indicator does not light, adjust RV2 to the point
3. If the TUNED indicator does not light, adjust RV2 to the point
(moment) when the TUNED indicator will change from going
off to going on.
off to going on.
Adjustment Location: MAIN board
SECTION 4
ELECTRICAL ADJUSTMENTS
AM RF SSG
loop antenna
set
loop antenna
(Supplied accessories)
60 cm
AM ANTENNA
terminal
30% amplitude
modulation by
400 Hz signal
Carrier frequency : 999 kHz (at 9 k step)
1,000 kHz (at 10 k step)
Output level
: 25 dB
Field strength dB (
µ
V/m) =SSG output level dB (
µ
V/m) –26 dB.
Carrier frequency : 98 MHz
Modulation
Modulation
: AUDIO 1 kH, 75 kHz
deviation (100%)
Output level
: 26 dB
µ
(17.8
µ
V)
FM ANTENNA terminal
(75
(75
Ω
open)
75
Ω
coaxial
set
FM RF stereo signal
generator
generator
RV1
IC1
FE1
RV2
Adjustment Location:
[MAIN BOARD] (Component Side)
ST-EX880/MS717
– 7 –
– 8 –
SECTION 5
DIAGRAMS
5-1.
NOTE FOR PRINTED WIRING BOARDS AND SCHEMATIC DIAGRAMS
Note on Schematic Diagram:
• All capacitors are in µF unless otherwise noted. pF: µµF
• All capacitors are in µF unless otherwise noted. pF: µµF
50 WV or less are not indicated except for electrolytics
and tantalums.
and tantalums.
• All resistors are in
Ω
and
1
/
4
W or less unless otherwise
specified.
•
¢
: internal component.
•
2
: nonflammable resistor.
•
C
: panel designation.
Note on Printed Wiring Boards:
• X
: parts extracted from the component side.
•
¢
: internal component.
• Indication of transistor.
Abbreviation:
HK
: Hong Kong
JE
: Tourist
MY
: Malaysia
SP
: Singapore
•
U
: B+ Line.
•
V
: B– Line.
•
H
: adjustment for repair.
• Voltages and waveforms are dc with respect to ground
under no-signal (detuned) conditions.
no mark : FM
(
no mark : FM
(
) : AM (MW)
〈〈
〉〉
: STAND BY
[
] : MUTING ON
• Voltages are taken with a VOM (Input impedance 10 M
Ω
).
Voltage variations may be noted due to normal produc-
tion tolerances.
tion tolerances.
• Waveforms are taken with a oscilloscope.
Voltage variations may be noted due to normal produc-
tion tolerances.
tion tolerances.
• Circled numbers refer to waveforms.
• Signal path.
• Signal path.
F
: FM
f
: AM (MW)
Note: The components identified by mark
!
or dotted line
with mark
!
are critical for safety.
Replace only with part number specified.
B
These are omitted.
C
E
Q
• Circuit Boards Location
• Waveforms
– MAIN Section –
– MAIN Section –
1
IC51
1
(XIN)
2
IC201
$¡
(X2)
3
IC201
$¢
(XT2)
2.9Vp-p
4.5 MHz
– PANEL Section –
4
IC901
@º
(XOUT)
5
IC901
@¡
(XIN)
4.4Vp-p
10 MHz
4.8Vp-p
32.768 kHz
5.2Vp-p
513 kHz
880 mVp-p
504 kHz
AC OUTLET board
(Tourist model)
(Tourist model)
TRANSFORMER board
PANEL board
RDS board
(ST-EX880)
(ST-EX880)
MAIN board
ST-EX880/MS717
D1
F-1
D2
E-2
D103
G-7
D104
E-7
D105
E-6
D125
B-5
D143
D-6
D161
D-7
D191
D-2
D272
G-8
D281
H-4
D282
G-4
IC1
E-4
IC51
C-2
IC111
C-7
IC171
I-6
IC201
G-6
Q1
C-4
Q2
C-4
Q9
C-4
Q10
C-5
Q11
A-3
Q12
A-4
Q13
A-4
Q14
B-4
Q15
B-4
Q55
E-2
Q121
B-5
Q122
B-5
Q123
C-5
Q141
D-6
Q142
D-6
Q201
F-6
Q202
B-6
Q203
B-7
Q273
G-8
Q274
G-8
Q281
H-4
– 9 –
– 10 –
5-2.
PRINTED WIRING BOARD – MAIN Section – (ST-EX880)
•
See page 7 for Circuit Boards Location.
• Semiconductor
Location
Ref. No.
Location
(Page 21)
(Page 20)
(Page 24)
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