Sharp RTXV-300-H Service manual
SERVICE MANUAL
B C
RT-XV300H
RT-XV300H
No. S4727RTXV300H
Dolby noise reduction manufactured under license from
Dolby Laboratories Licensing Corporation.
“DOLBY” and the double-D symbol are trademarks of
Dolby Laboratories Licensing Corporation.
• In the interests of user-safety the set should be restored to its
original condition and only parts identical to those specified
should be used.
CONTENTS
Page
IMPORTANT SERVICE NOTES (FOR UK ONLY) ..............................................................................................................2
WIRING OF PRIMARILY SUPPLY LEADS (FOR UK ONLY) .............................................................................................2
SPECIFICATIONS ............................................................................................................................................................... 3
NAMES OF PARTS .............................................................................................................................................................3
DISASSEMBLY....................................................................................................................................................................4
ADJUSTMENT .....................................................................................................................................................................5
BLOCK DIAGRAM ............................................................................................................................................................... 6
SCHEMATIC DIAGRAM / WIRING SIDE OF P.W.BOARD................................................................................................. 8
FUNCTION TABLE OF IC..................................................................................................................................................12
NOTES ON SCHEMATIC DIAGRAM ................................................................................................................................14
TYPES OF TRANSISTOR AND LED.................................................................................................................................14
REPLACEMENT PARTS LIST / EXPLODED VIEW
PACKING OF THE SET (FOR UK ONLY)
SHARP CORPORATION
MECHANISM SECTION
1
VR101
L-ch
P. B. AMP.SENS.
VR103
VR104
VR105 VR106
TP101
TP102
VR102
23
432
1
MAIN PWB
L-ch
BIAS
R-ch
BIAS
R-ch
P. B. AMP.SENS.
L-ch
REC. AMP.SENS.
R-ch
REC. AMP.SENS.
L-ch
GND
GND
R-ch
L-ch
GND
R-ch
• Driving Force Check
Specified ValueTorque Meter
Play: TW-2412 80 g or more
Reverse Play: TW-2422 80 g or more
• Checking the playback/FF/rewinding torque
Torque Meter Specified Value
Play: TW-2111 25 to 65 g. cm
Reverse Play: TW-2121 25 to 65 g.cm
Fast forward: TW-2231 60 to 130 g.cm
Rewind: TW-2231 60 to 130 g.cm
ADJUSTMENT
Adjusting the deck circuit
• Checking the bias oscillation frequency
Adjusting object Set value Connection
— 85 ±7kHZ TP101 1 or 3
• Checking the bias current
Adjusting object Set value Connection
L: VR105 Standard: 15 ± 3 mV L: TP101 1
R: VR106 R: TP101 3
• Adjusting the playback amplifier sensitivity
Test Tape
MTT-150 L: VR101 Standard: 580mV L:TP102 1
RT-XV300H
Connection Set value
R: VR102 R: TP102 4
Connection
• Adjusting the record/playback head azimuth
ConnectionTest Tepe
MTT - 114 Output: L: TP102 1 R: TP102 4
* Raise the cassette holder cover and remove it , and then
adjust the azimuth.
• Adjusting the record/playback amplifier sensitivity
Connection
UR-121 Record level control 200mV Input:AUX
L: VR103 200mV Output:
R: VR104 L: TP102 1
TP101 pin or pin
Set value ConnectionTest Tape
(1kHz)
R: TP102 4
1 3
Record mode
560kΩ
Electronic voltmeter
Unit
560Ω
GND (TP101pin )
Figure 5-1 BIAS CURRENT
2
Figure 5-2 ADJUSTMENT POINTS
– 5 –
RT-XV300H
RECORD/PLAYBACK
HEAD
A+12V
IC102
BA3126N
HEAD
SELECTOR
3
9
7
6
8
BIAS
ADJUSTMENT
VR105
VR106
EQUALIZER AMP.
IC101
M51167BFP
8
A+12V
1
4
2
34
P/B
4
33
REC
R/P
SELECTOR
14
13
24
15
ALC
P/B
APSS
R/P
PBCR
29
11
26
7
30
APSS
18
PBCR
22
23
28
9
25
12
P.B.AMP.
SENS.
VR101
VR102
REC.AMP.
REC
SENS.
VR103
VR104
APSS
CONTROL
3
28
15
16
DOLBY NR
B/C/OFF
DOLBY
Q138
9
22
1
IC103
30
CONTROL
DOLBY NR
NA12142NT
2
5
R/P
26
MUTE
A+12V
MUTE
Q115
Q116
Q137
Q151
Q152
ERASE HEAD
BIAS OSC.
Q120,Q121
L107
PH401
PHOTE
INTERRUPTER
SOL401
SOLENOID
SW403
TAPE MAIN
SW404
TAPE SIDE A
ERASE PREVENTION
SW406
TAPE METAL
DETECTION
SW401
TAPE CASSETTE
DETECTION
SW405
TAPE CrO
DETECTION
SW402
TAPE SIDE B
ERASE PREVENTION
2
RECORD/
PLAYBACK
SELECTOR
Q127
Q128
HALL
ELEMENT
EQUALIZER
SELECTOR
Q101~Q112
A+12V
BIAS ON/OFF
Q124
CrO
2
SELECTOR
Q122,Q126
METAL SELECTOR
Q123,Q125
WAVE FROM
SHAPING
SOLENOID
DRIVER
Q131
TAPE MOTOR
M251
Q130
M
A+12V
+5V
M+10V
–
+
Q136
M+10V
Q129
MOTOR
DRIVER
ALC
CONTROL
Q153
Q154
BIAS SELECTOR
CONTROL
Q117
Q118
Q119
Q133
Q134
DOLBY SELECTOR
TAPE MECHANISM UNIT
Figure 6 BLOCK DIAGRAM (1/2)
– 6 –
MUTE
Q115
Q116
Q137
Q151
Q152
EMITTER
AMP.
+5V
M+10V
POWER
CONTROL
Q139
Q140
IC104
M5278L05
VOLTAGE
REGULATOR
IC106
NJM78M10FA
VOLTAGE
REGULATOR
A+12V
Q146
Q145
VOLTAGE
REGULATOR
BASIC+B
F101
T800mA L 250V
RECORD SIGNAL
PLAYBACK SIGNAL
MICON CONTROL
POWER
POWER
TRANSFORMER
T101
RT-XV300H
AC 230V
50Hz
AC POWER
SUPPLY CORD
SELECTOR
+5V
25
MUTE
27
DOLBY_B
26
DOLBY_C
28
REC CNT
23
DOLBY B/C APSS
30
BIAS
29
2
RP
CrO
1
MOTOR
32
SOL
31
TAPE PLS IN
22
MKEY2
21
MKEY1
18
5V
5V
17
D114~D117
PCNT-IN
T-RDY
T-CLK
T-DATA
T-CMD
RESET
FWD
REV
REC
REV1
REV2
REV3
KEY1
X OUT
X IN
CONTROL
POWER
CONTROL
11
6
8
9
10
12
2
3
4
5
7
24
20
14
15
POWER
Q156
Q157
Q160
Q135
T.F.
SOC101
RESET
LED BLOCK
LED101~LED109
SW101~SW108
BUTTON
BLOCK
14
1
6
2
MD-XV300H
4
MD-XV300H(BR)
FROM
10
AMP. UNIT
11
12
13
15
IC105
IX0142AW
TAPE
MICROCOMPUTER
Figure 7 BLOCK DIAGRAM (2/2)
– 7 –
X101
6MHz
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