Sony HCD-RG66 / MHC-RG66 Service Manual ▷ View online
16
HCD-RG66
SECTION 4
ELECTRICAL ADJUSTMENTS
FM Tuned Level Adjustment
Procedure:
1.
1.
Supply a 98 MHz signal at 28 dB from the ANTENNA terminal.
2.
Tune the set to 98 MHz.
3.
Adjust RV101 to the point (moment) when the TUNED
indicator will change from going off to going on.
indicator will change from going off to going on.
Adjustment Location: MAIN board
Null Adjustment
Procedure:
1.
1.
Supply a 98 MHz signal at 60 dB from the ANTENNA terminal.
2.
Tune the set to 98 MHz.
3.
Measure voltage between pin 21 and pin 23 of IC 101. Adjust
T101 until the voltage becomes 0 V.
T101 until the voltage becomes 0 V.
Adjustment Location: MAIN board
[MAIN BOARD] Component side
FM RF Signal generator
75
Ω
coaxial
Carrier frequency : 98 MHz
Modulation : AUDIO 1 kHz, 75 kHz
deviation (100%)
Output level : 30 dB (at 75
Modulation : AUDIO 1 kHz, 75 kHz
deviation (100%)
Output level : 30 dB (at 75
Ω
open)
FM ANTENNA terminal
(JK101)
(JK101)
set
FM RF Signal generator
75
Ω
coaxial
Carrier frequency : 98 MHz
Modulation : AUDIO 1 kHz, 75 kHz
deviation (100%)
Output level : 60 dB (at 75
Modulation : AUDIO 1 kHz, 75 kHz
deviation (100%)
Output level : 60 dB (at 75
Ω
open)
FM ANTENNA terminal
(JK101)
(JK101)
set
T101: NULL
IFT101: AM IF
RV101:
FM TUNED LEVEL
FM TUNED LEVEL
AM RF Signal generator
30% amplitude
modulation by
400Hz signal
output level : as low as possible
modulation by
400Hz signal
output level : as low as possible
AM ANTENNA terminal
(JK101)
(JK101)
set
AM IF Adjustment
TUNER SECTION
Procedure:
1.
1.
Set the frequency of the AM RF signal generator to 1000 kHz
(at 10 kHz step) or 999 kHz (at 9 kHz step).
(at 10 kHz step) or 999 kHz (at 9 kHz step).
2.
Tune the set to AM 1000 kHz (at 10 kHz step) or 999 kHz (at 9
kHz step).
kHz step).
3.
Adjust IFT101 so that the reading on level meter becomes in
maximum.
maximum.
headphones jack (JK801)
level meter
set
16
Ω
17
HCD-RG66
CN731
TP731:
TP connected to pin
TP connected to pin
q;
(IC751)
IC751
CN733
IC731
Adjustment Location: BD board
[BD BOARD] (Component Side)
CD SECTION
RF Level Check
Procedure :
1. Connect an oscilloscope to pin q; (IC751).
2. Turn the power on.
3. Load a disc (YEDS-18) and playback the number five track.
4. Confirm that oscilloscope waveform is clear and check RF signal
1. Connect an oscilloscope to pin q; (IC751).
2. Turn the power on.
3. Load a disc (YEDS-18) and playback the number five track.
4. Confirm that oscilloscope waveform is clear and check RF signal
level is correct or not.
IC751 pin
q;
GND
BD board
oscilloscope
Note :
Clear RF signal waveform means that the shape “
◊
” can be clearly
distinguished at the center of the waveform.
RF signal waveform
VOLT/DIV : 200mV
TIME/DIV : 500ns
TIME/DIV : 500ns
level : 1.4 to 2.1 Vp-p
Note :
1. CD Block is basically designed to operate without adjustment.
Therefore, check each item in order given.
2. Use YEDS-18 disc (3-702-101-01) unless otherwise indicated.
3. Use an oscilloscope with more than 10M
3. Use an oscilloscope with more than 10M
Ω
impedance.
4. Clean the object lens by an applicator with neutral detergent
when the signal level is low than specified value with the
following checks.
following checks.
18
HCD-RG66
SECTION 5
DIAGRAMS
Note on Schematic Diagram:
• All capacitors are in
• All capacitors are in
µ
F unless otherwise noted. pF:
µµ
F
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.
•
f
: internal component.
•
C
: panel designation.
Note on Printed Wiring Boards:
• X
: parts extracted from the component side.
• b
: Pattern from the side which enables seeing.
• Indication of transistor.
•
A
: B+ Line.
•
B
: B– Line.
•
H
: adjustment for repair.
• Voltages and waveforms are dc with respect to ground
under no-signal (detuned) conditions.
• Voltages are taken with a VOM (Input impedance 10 M
Ω
).
Voltage variations may be noted due to normal produc-
tion tolerances.
no mark : FM
<
tion tolerances.
no mark : FM
<
> : CD
[
] : TAPE
• 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.
F
: FM
E
: PB (DECK A)
d
: PB (DECK B)
G
: REC (DECK B)
J
: CD
c
: DIGITAL OUT
• Abbreviation
AUS
: Australian model.
SP
: Singapore model.
THIS NOTE IS COMMON FOR PRINTED WIRING BOARDS AND SCHEMATIC DIAGRAMS.
(In addition to this, the necessary note is printed in each block.)
(In addition to this, the necessary note is printed in each block.)
C
B
These are omitted.
E
Q
B
These are omitted.
C
E
Q
Note: The components identified by mark
0
or dotted line
with mark
0
are critical for safety.
Replace only with part number specified.
19
19
HCD-RG66
5-1. Circuit Boards Location
• Waveforms
KEYBOARD board
PANEL board
SUB TRANS board
MAIN board
BD board
MIC board
SENSOR board
TRANS board
VIDEO OUT board
POWER board
DRIVER board
MOTOR board
SPDL MOTOR board
ADDRESS SENSOR board
REM board
SURROUND board
5
Q223 Collector
(TAPE REC mode)
(TAPE REC mode)
2
IC801
qd
(XT2)
1
IC751
rf
(XOUT)
4
IC102
ws
(XOUT)
2 V/DIV, 100 ns/DIV
5 V/DIV, 4 s/DIV
2 V/DIV, 10 s/DIV
2 V/DIV, 20 ns/DIV
3
IC801
qh
(CF2)
2 V/DIV, 40 ns/DIV
5.2 Vp-p
5.6 Vp-p
59 ns
222 ns
30.5 s
4.9 Vp-p
100 ns
5.0 Vp-p
15 Vp-p
13 s
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