Sony XR-C7220 User manual

MICROFILM
SERVICE MANUAL US Model
Canadian Model
XR-C7220
E Model
XR-C7300/C7300W
Model Name Using Similar Mechanism XR-C5100
Tape Transport Mechanism Type MG-25G-136
SPECIFICATIONS
XR-C7220/C7300/C7300W
For RM-X4S (Remote Commander),
please refer to RM-X4S Service Manual
(9-925-698-∏) previously issued.
– Continued on next page –
FM/AM (MW/SW)
CASSETTE CAR STEREO
Photo: XR-C7300
Dolby noise reduction manufactured under license
from Dolby Laboratories Licensing Corporation.
“DOLBY”and thedouble-Dsymbolaare trademarks
of Dolby Laboratories Licensing Corporation.

– 2 –
TABLE OF CONTENTS
1. GENERAL
Location of Controls ....................................................... 3
Setting the Clock ............................................................. 3
Installation....................................................................... 4
Connections ..................................................................... 6
2. DISASSEMBLY ......................................................... 8
3. ASSEMBLY OF MECHANISM DECK........... 10
4. MECHANICAL ADJUSTMENTS ....................... 13
5. ELECTRICAL ADJUSTMENTS
Test Mode ........................................................................ 13
Tape Deck Section .......................................................... 13
Tuner Section .................................................................. 14
6. DIAGRAMS
6-1. Note for Printed Wiring Boards and
Schematic Diagrams ....................................................... 17
6-2. Schematic Diagram – MAIN Section (1/3) –................. 19
6-3. Schematic Diagram – MAIN Section (2/3) –................. 21
6-4. Schematic Diagram – MAIN Section (3/3) –................. 23
6-5. Printed Wiring Board
– MAIN Board (Component Side) – .............................. 25
6-6. Printed Wiring Board
– MAIN Board (Conductor Side) – ................................ 27
6-7. Printed Wiring Boards – PANEL Section – ................... 29
6-8. Schematic Diagram – PANEL Section – ........................ 31
6-9. IC Pin Function Description ........................................... 35
7. EXPLODED VIEWS................................................ 39
8. ELECTRICAL PARTS LIST ............................... 42
Flexible Circuit Board Repairing
• Keep the temperature of the soldering iron around 270 ˚C dur-
ing repairing.
• Do not touch the soldering iron on the same conductor of the
circuit board (within 3 times).
• Be careful not to apply force on the conductor when soldering
or unsoldering.
Notes on chip component replacement
• Never reuse a disconnected chip component.
• Notice that the minus side of a tantalum capacitor may be dam-
aged by heat.

– 3 –
SECTION 1
GENERAL This section is extracted from
instruction manual.

– 4 –

– 5 –

– 6 –

– 7 –

– 8 –
SUB PANEL ASS’Y
MECHANISM DECK (MG-25G-136)
Note: Follow the disassembly procedure in the numerical order given.
SECTION 2
DISASSEMBLY
3 claw
3 two claws
1 screw
(PTT2.6
× 8
)
5 sub panel ass’y
2 five screws
(PTT2.6
× 8)
4 connector
(CN500)
3 flexible flat cable
(CN301)
4 mechanism deck
(MG-25G-136)
1 screw
(PTT2.6
× 6)
2 connector
(CN302)

– 9 –
MAIN BOARD, HEAT SINK
3 two ground point
screws
5 three screws
(PTT2.6
× 8)
5 two screws
(PTT2.6
× 10)
1 screw
(PTT2.6
× 8)
5 three screws
(PTT2.6
× 8)
6 heat sink
2 rubber cap (25)
1 two screws
(PTT2.6
× 8)
4 main board

– 10 –
SECTION 3
ASSEMBLY OF MECHANISM DECK
HOUSING
ARM (SUCTION)
Note: Follow the assembly procedure in the numerical order given.
A part
C part
B part
D part
8 Hold the hanger by
bending the claw.
6 Fit projection on D part.
4 Fit claw on B part.
3 Put the housing
under A part.
5 Fit projection on C part.
1 Install the catch to the hanger.
2 Install the hanger onto
two claws of the housing.
7 Holder the hanger by bending the claw.
hanger
housing
2 Move the arm (suction) in the arrow
direction and fit on projection.
1 Fit the arm (suction) on the shaft.
projection

– 11 –
LEVER (LDG-A)/(LDG-B)
GEAR (LDG-FT)
shaft A
shaft B
shaft C
1
Fit the lever (LDG-A) on
shafts A – C and install it.
shaft A
shaft B
2
Fit the lever (LDG-B) on
shafts
A and B and
install it.
3 type-E stop ring 2.0
gear (LDG-D)
5 gear (LDG-FT)
6 polyethylene washer
2 tension spring (LD-2)
2 tension spring (LD-1)
gear (LDG-FB)
lever (LDG-A)
hole
hole
4 Align hole in the gear (LDG-D)
with hole the lever (LDG-A).
3 Move the lever (LDG-B)
in the arrow direction.
1

– 12 –
GUIDE (C)
2 guide (C)
1 three claws
MOUNTING POSITION OF CAPSTAN/REEL MOTOR (M901)
two precision screws
(P2
× 2)
capstan / reel moto
r
(M901)
30˚

– 13 –
SECTION 4
MECHANICAL ADJUSTMENTS SECTION 5 ELECTRICAL ADJUSTMENTS
TEST MODE
This set have the test mode function. In the test mode, FM Auto
Scan/Stop Level and MW Auto Scan/Stop Level adjustments can
be performed easier than it in ordinary procedure.
<Set the Test Mode>
1. Set the “power select” switch (S501) is “A (ON)” position.
2. Turn ON the regulated power supply. (All LEDs on the set
lights up, and the clock is displayed.)
Note: Press the [OFF] button, if the clock is not displayed.
3. Push the preset [4] button.
4. Push the preset [5] button.
5. Press the preset [1] button for more than two seconds.
6. Then the display indicates all lights, the test mode is set.
<Release the Test mode>
1. Push the [OFF] button.
2. Return the “power select” switch (S501) to initially set posi-
tion.
Tape Speed Adjustment
Setting:
Procedure:
1. Put the set into the FWD PB mode.
2. Adjust adjustment resistor for inside capstan motor so that the
reading on the speed checker or frequency counter becomes in
specification.
Specification: Constant speed
Adjustment Location: See page 16.
See the adjustment location from on page 15 for the
adjustment.
0 dB=0.775 V
TAPE DECK SECTION
Speed checker Frequency counter
–1.5 to +2.5% 2,955 to 3,075 Hz
Mode Tension Meter Meter Reading
Forward CQ-403A more than 90 g
(more than 3.18 oz)
Reverse CQ-403R more than 90 g
(more than 3.18 oz)
•TapeTension Measurement
1. Clean the following parts with a denatured-alcohol-moistened
swab:
playback head pinch roller
rubber belt capstan
idlers
2. Demagnetize the playback head with a head demagnetizer.
3. Do not use a magnetized screwdriver for the adjustments.
4. After the adjustments, apply suitable locking compound to the
parts adjusted.
5. The adjustments should be performed with the power supply
voltage unless otherwise noted.
•Torque Measurement
Mode Torque Meter Meter Reading
Forward CQ-102C 30 – 65 g•cm
(0.42 – 0.90 oz•inch)
Forward CQ-102C 0.5 – 4.5g•cm
Back Tension (0.01 – 0.06 oz•inch)
Reverse CQ-102RC 30 – 65 g•cm
(0.42 – 0.90 oz•inch)
Reverse CQ-102RC 0.5 – 4.5g•cm
Back Tension (0.01 – 0.06 oz•inch)
FF, REW CQ-201B 60 – 200 g•cm
(0.83 – 2.78 oz•inch)
set +–
test tape
WS-48A
(3 kHz, 0 dB)
AUDIO OUT REAR jack (CNJ151)
10 k Ω
speed checker
or
frequency counter

– 14 –
Dolby Level Adjustment
Setting:
[SHIFT] button : ON
Preset [3] (PLAY MODE) and
[4](→) buttons : NR OFF
SOUND (BAS) button : Center
SOUND (TRE) button : Center
SOUND (BAL) button : Center
SOUND (FAD) button : Center
SOUND (VOL) button : Maximum
D-BASS control : OFF
Procedure:
1. Put the set into the FWD PB mode.
2. Adjust RV101 (L-CH) and RV201 (R-CH) so that the level
meter reading is –6±0.5 dB (0.37 to 0.41 V).
Adjustment Location: See page 16.
set +
–
test tape
P-4-D400
(400Hz, 0 dB) level mete
r
MAIN board
MAIN board
TP (GND)
TP (DOLBY-L)/
TP (DOLBY-R)
      
TUNER SECTION
Cautions during repair
When the tuner unit is defective, replace it by a new one be-
cause its internal block is difficult to repair.
Note: Adjust the tuner section in the sequence shown below.
1. FM Auto Scan/Stop Level Adjustment
2. FM Stereo Separation Adjustment
3. MW Auto Scan/Stop Level Adjustment
FM Auto Scan/Stop Level Adjustment
Setting:
[SOURCE] button: FM
FREQUENCY SELECT switch: FM200 k
Procedure:
1. Set to the test mode. (See page 13)
2. Push the [SOURCE] button and set to FM.
Display
3. Adjust with the volume RV2 on TU1 so that the “FM” indica-
tion turns to “FM0” indication on the display window.
But, in case of already indicated “FM0”, turn the RV2 so that
put out light “0” indication and adjustment.
Display
Adjustment Location: See page 16.
FM RF signal
generator
Carrier frequency : 97.9 MHz
Output level : 22 dB (12.6
µ V)
Mode : mono
Modulation : 1 kHz, 75 kHz deviation
0.01 µ F
set
antenna jack (J1)
(XR-C7300/C7300W only)
0 dB=1 µV
XR-C7220, the tuner section has no adjustment.
SHUF
SHUF

– 15 –
FM Stereo Separation Adjustment
Setting:
[SOURCE] button : FM
FREQUENCY SELECT switch : FM 200 k
Procedure:
FM Stereo Level meter Level meter
signal generator connection reading (dB)
output channel
L-CH L-CH A
B
R-CH L-CH Adjust RV4 on TU1
for minimum reading.
R-CH R-CH C
D
L-CH R-CH Adjust RV4 on TU1
for minimum reading.
L-CH Stereo separation: A-B
R-CH Stereo separation: C-D
The separations of both channels should be equal.
Specification: Separation more than 30 dB
Adjustment Location: See page 16.
FM RF signal
generator
Carrier frequency : 97.9 MHz
Output level : 70 dB (3.2 mV)
Mode : stereo
Modulation : main: 1 kHz, 33.75 kHz deviation (45%)
sub: 1 kHz, 33.75 kHz deviation (45%)
19 kHz pilot: 7.5 kHz deviation (10%)
0.01 µ F
set
antenna jack (J1)
+
–
AUDIO OUT REAR jack
(CNJ151)
level meter
10 k
Ω
MW Auto Scan/Stop Level Adjustment
Setting:
[SOURCE]and[MODE]buttons : MW
FREQUENCY SELECT switch : MW 10 k
AM RF signal
generator
Carrier frequency : 1000 kHz
30% amplitude
modulation by
1 kHz signal
Output level : 33 dB (44.7
µ
V)
(50 Ω )set
AM dummy antenna
30 Ω
15 pF
65 pF
antenna jack (J1)
Procedure:
1. Set to the test mode. (See page 13)
2. Push the[SOURCE]button and set to FM.
3. Push the[MODE]button and set to MW.
Display
4. Adjust with the volume RV1 on TU1 so that the “MW” indi-
cation turns to “MW0” indication on the display window.
But, in case of already indicated “MW0”, turn the RV1 so that
put out light “0” indication and adjustment.
Display
Adjustment Location: See page 16.
TP SHUF
TP SHUF

– 16 –
Adjustment Location:
– SET UPPER VIEW –
– SET BOTTOM VIEW –
TP (DOLBY-R) Dolby Level
Adjustment
TP (GND)
TP (DOLBY-L)
Tape Speed Adjustment
RV201
(R-CH) RV101 (L-CH)
Dolby Level
Adjustment
    
TU1 (XR-C7300/C7300W only)
RV1 MW Auto Scan/Stop Level Adjustment
RV2 FM Auto Scan/Stop Level Adjustment
RV4 FM Stereo Separation Adjustment

– 17 –
6-1. NOTE FOR PRINTED WIRING BOARDS AND SCHEMATIC DIAGRAMS
Note on Printed Wiring Board:
•X: parts extracted from the component side.
•Y: parts extracted from the conductor side.
•b: Pattern from the side which enables seeing.
(The other layers' patterns are not indicated.)
Caution:
Pattern face side: Partsonthe patternface sideseenfrom
(Conductor Side) the pattern face are indicated.
Parts face side: Parts on the parts face side seen from
(Component Side) the parts face are indicated.
Note on Schematic Diagram:
• All capacitors are in µF unless otherwise noted. pF: µµF
50 WV or less are not indicated except for electrolytics
and tantalums.
• All resistors are in Ωand 1/4W or less unless otherwise
specified.
• % : indicates tolerance.
•¢: internal component.
•C: panel designation.
•U: B+ Line.
•H: adjustment for repair.
• Powervoltage isdc14.4V andfed with regulateddcpower
supply from ACC and BATT cords.
• Voltages and waveforms are dc with respect to ground
under no-signal (detuned) conditions.
no mark : FM
( ) : MW
[ ] : SW
〈〈 〉〉 :TAPE PLAY
∗: Impossible to measure
• Voltages aretakenwith aVOM(Inputimpedance10 MΩ).
Voltage variations may be noted due to normal produc-
tion tolerances.
• Waveforms are taken with a oscilloscope.
Voltage variations may be noted due to normal produc-
tion tolerances.
• Circled numbers refer to waveforms.
• Signal path.
F: FM
f: AM (MW/SW)
E:TAPE PLAY
L: BUS AUDIO IN
SECTION 6
DIAGRAMS

– 18 –
• Waveforms
– MAIN Board –
1IC1 2(OSC OUT)
2IC501 &¢ (X0A)
3IC501 (™ (X0)
– KEY Board –
1IC901 ^º OSC
1.2 Vp-p
0.1
µ s
3.6 Vp-p
30
µ s
4.1 Vp-p
270 ns
2.7 Vp-p
27 µ s

XR-C7220/C7300/C7300W
– 19 – – 20 –
6-2. SCHEMATIC DIAGRAM – MAIN Section (1/3) – • See page 18 for Waveforms. •See page 33 for IC Block Diagrams.
(Page 23)
(Page 21)

XR-C7220/C7300/C7300W
– 21 – – 22 –
6-3. SCHEMATIC DIAGRAM – MAIN Section (2/3) – • See page 18 for Waveforms. •See page 33 for IC Block Diagrams.
(Page
20)
(Page 23)