Sharp QT-90W Service Manual Download Page 8

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QT-90W

– 8 –

MECHANISM SECTION

Head

Playback test tape

Connect VTVM and oscilloscope to

Head fixing screw

Adjust to get MAX.

adjustment

MTT-113 6.3 kHz

speaker output

(see Fig 8-3.)

audio output

Bias Frequency

Record position

Connect frequency counter to TP5 and

Adjust T201

80 kHz

1 kHz

adjustment

ground

(Bias Oscillation)

Beat cancel

Record position

Same as step 3

S201 from playback

75 kHz

0.5 kHz

to record

Step

Item

Condition

Connection

Adjust

Output

TAPE Section

Figure 8-1 ADJUSTMENT POINTS

Figure 8-3

Erase Head

Head fixing
screw

Record/
Playback
Head

Tape Mechanism

Figure 8-2 ADJUSTMENT POINTS

TP2

FM BAND
COVERAGE

FM
DETECTION

BIAS

OSCILLATION

FM
TRACKING

fL
fH

MW BAND
COVERAGE fH

MW
TRACKING fH

T105

T104

T103

CT101

CT102

T106

VR102

IC102

T102

CT104

T107

T101

CT103

T108

TUNER P.V.C.

L103

IC101

L102

T201

IC201

MAIN PWB

L109

MW BAR ANTENNA

TC1

TC2

TC3

TC4

MW BAND
COVERAGE fL

SW1 BAND
COVERAGE

SW1
TRACKING

fL
fH

SW2
TRACKING

SW2 BAND
COVERAGE

MW IF

FM IF

S201

RECORD/PLAYBACK

MW
TRACKING fL

VCO

ROD

ANTENNA

TP5

TP1

TP3

TP4

17
18

TP6

R227

C220

C221

BIAS

OSCILLATION

T201

IC201

MAIN PWB

S201

RECORD/PLAYBACK

REC

PLAY
BACK

ERASE HEAD

RECORD/

PLAYBACK HEAD

TAPE

CN602

M601

TAPE

MOTOR

SW601

TAPE MAIN

CN201

CON201

1
2
3
4

CON602

TP5

R227

C220

C221

Summary of Contents for QT-90W

Page 1: ... 2 battery x 10 40 W MPO 36 W 18 W 18 W AC operation 10 T H D RMS 20 W 10W 10W DC operation 10 T H D 8 cm 3 1 8 full range speaker x 4 Headphones 16 50 ohms recommended 32 ohms Mixing microphone 600 ohms Line input 350 mV 47 kohms Width 520 mm 20 1 2 Height 191 mm 7 1 2 Depth 216 mm 8 1 2 4 7 kg 10 4 lbs without batteries General Power source Power consumption Output power Speakers Output terminal...

Page 2: ...ord Button 04 Play Button 05 Rewind Button 06 Fast Forward Button 07 Stop Eject Button 08 Pause Button 09 Volume Control 10 Band Selector 11 Extra Bass Control 12 Graphic Equalizer Controls 13 Built in Microphone 14 Sound Level Meter 15 Surround Button 16 Fine Tuning Control 17 Tuning Control 18 Mixing Microphone Socket 19 Line Input Sockets 20 AC Voltage Selector 21 AC Input Socket 22 Battery Com...

Page 3: ...ove the power supply plug from the wall outlet before starting to disassemble the unit 3 Take off nylon bands or wire holders where they need to be removed when disassembling the unit After servicing the unit be sure to rearrange the leads where they were before disassembling 4 Take sufficient care on static electricity of integrated circuits and other circuits when servicing Figure 3 4 How to att...

Page 4: ...tract the erase head upward Note After replacing the heads and performing the azimuth adjustment be sure to apply screwlock How to remove the pinch roller See Fig 4 4 1 Remove the screw B1 x 1 pc and remove the pinch roller upwards Figure 4 3 Figure 4 4 REMOVING AND REINSTALLING THE MAIN PARTS Pinch Roller B1 x1 ø1 5x2 5mm J1 x4 ø3x10mm Tape Mechanism Stop Eject Buttom Push Open Cassette Holder K1...

Page 5: ...ote When mounting the motor pay attention to the motor bracket angle Figure 5 1 Figure 5 2 How to remove the flywheel See Fig 5 3 1 Remove the belt See Fig 5 1 2 Remove the stop washer E1 x 1 pc with a small precision screwdriver to extract the flywheel from the capstan metal Note When the stop washer is deformed or damaged replace it with a new one How to reinstall the parts Install each part in ...

Page 6: ...end 87 4 MHz 4 Repeat step 2 3 until no further improvement can be made 5 FM TRACKING Same as step 2 Same as step 2 Same as step 1 Adjust P V C TC2 to Tune P V C to fH 106 MHz get MAX output 106 MHz 6 FM TRACKING Same as step 2 Same as step 2 Same as step 1 Adjust L102 to get MAX Tune P V C to fL 90 MHz output 90 MHz 7 Repeat step 5 6 and then step 2 3 5 6 until no further improvement can be made ...

Page 7: ...sition oscilloscope 3 Tune P V C to 3 Power supply high end 2 SW1 BAND Same as step 1 Same as step 1 Same as step 1 Adjust T104 get MAX Tune P V C to low COVERAGE fL output at 2 25 MHz end 2 25 MHz 3 Repeat step 1 2 until no further improvement can be made 4 SW1 Same as step 1 Same as step 1 Same as step 1 Adjust CT104 get MAX Tune P V C to 6 MHz TRACKING fH output at 6 MHz 6 MHz 5 SW1 Same as ste...

Page 8: ...pe Mechanism Figure 8 2 ADJUSTMENT POINTS TP2 FM BAND COVERAGE FM DETECTION BIAS OSCILLATION FM TRACKING fL fH MW BAND COVERAGE fH MW TRACKING fH T105 T104 T103 CT101 CT102 T106 VR102 IC102 T102 CT104 T107 T101 CT103 T108 TUNER P V C L103 IC101 1 9 L102 T201 IC201 MAIN PWB L109 MW BAR ANTENNA TC1 TC2 TC3 TC4 MW BAND COVERAGE fL SW1 BAND COVERAGE fH fL SW1 TRACKING fL fH SW2 TRACKING fL fH SW2 BAND...

Page 9: ... SS8550 E B C FRONT VIEW 3DA8050 FRONT VIEW FRONT VIEW CSL 326G3GTH 523HD IC101 LA1186N FM Pin No Voltage IC201 BA3313L PLAYBACK Pin No Voltage IC102 LA1805 FM Pin No Voltage Pin No Voltage IC102 LA1805 MW SW1 SW2 Pin No Voltage PinNo Voltage IC401 IC402 BA5415A Pin No Voltage Q603 SS8550 Pin No Voltage Q602 SS8550 Pin No Voltage Q205 2SC945 Pin No Voltage Q303 2SC945 Pin No Voltage Q304 2SC945 Pi...

Page 10: ...ML R211 18K C211 0 0022 ML T201 BIAS OSCILLATION C217 47P CH R256 10K R255 10K CON201 CN201 C231 0 018 ML C220 0 0068 ML C221 0 022 ML Q201 3DA8050 R228 10 C225 47 16 R227 22K C207 4 7 50 C208 4 7 50 C206 0 022 ML C201 0 0015 ML R204 39 R208 6 8K R201 3 9K C213 47 16 C259 680P R213 470K C258 33P CH C204 10 16 C202 0 0015 ML R202 3 9K IC201 BA3313L C209 0 0082 ML R215 47K C210 0 0082 ML R216 47K Q2...

Page 11: ... 250V CON601 CN601 T501 POWER TRANSFORMER CON401 CN401 R408 150 R407 150 JK401 HEADPHONES CON402 CN402B SP501 SURROUND L CH SP502 L CH S501 VOLTAGE SELECTOR S301 FUNCTION BEAT CANCEL Q501 2SC945 LD501 523HD LD502 523HD LD503 523HD LD504 523HD LD505 523HD LD508 CSL 326G3GTH LD507 CSL 326G3GTH R501 10K C502 10 16 C501 10 16 R505 10K R504 1K R502 120 R506 470 R503 120 R507 10K D501 1N4148 SW501 SURRO...

Page 12: ...214 C101 Q209 R255 R256 C225 R249 R248 R233 R222 R258 R257 R221 C224 R235 Q205 R226 Q207 R114 R116 C237 C125 C126 C129 C223 1 2 3 4 5 CON203 C134 TP4 R104 R118 C128 R115 R113 R103 R123 C110 C127 CF102 1 2 3 C122 C141 T107 C124 C123 R101 CF101 R117 D104 T108 D103 C109 C104 C106 C102 R122 C140 R102 L103 C108 C107 C139 C103 VC4 TC4 VC3 TC3 VC2 TC2 VC1 TC1 CT104 CT103 T101 T102 C115 R106 C116 C117 R10...

Page 13: ...RD R OR YL GR BL BROWN RED ORANGE YELLOW GREEN BLUE VL GY WH W BK PK VIOLET GRAY WHITE BLACK PINK AC POWER SUPPLY CORD AC 110 127 V AC 220 240 V 50 60 Hz JACK PWB A2 SW501 X BASS OFF ON A B SURROUND PWB A5 CN501 1 2 3 4 5 1 5 SO501 AC INPUT SOCKET AC 110 127 V AC 220 240 V 50 60 Hz RD RD BK S501 VOLTAGE SELECTOR AC 220 V 240 V AC 110 V 127 V BL BK WH T501 POWER TRANSFORMER 231 RD RD RD WH BL 230 B...

Page 14: ... ripple filter 62 IC201 BA3313L OUT 1 NF 1 IN 1 GND 150K IN 2 NF 2 ALC 150K ALC N C GND SUB VCC FILTER OUT 2 1 3 5 7 9 11 2 4 6 8 10 12 IC101 LA1186N VRE1 RF MIX REG BUTTER OSC IC102 LA1805 Vcc FM AM RF AMP MIX RNG OSC GND AGC AM IF DET LEVEL DET TUNING INDIC DRIVE FM IF DCT MUTING POST AMP PILOT DET PHASE DET DECODER VCO FF STEREO SW FF TNG STEREO INDIC DRIVE Vcc FF 3 5 1 2 20 17 16 11 13 15 14 2...

Page 15: ...type VC MF Cylindrical type without lead wire VC MN Cylindrical type without lead wire VC TV Square type without lead wire VC TQ Square type without lead wire VC CY Square type without lead wire VC CZ Square type without lead wire VC J The 13th character represents capacity difference J 5 K 10 M 20 N 30 C 0 25 pF D 0 5 pF Z 80 20 If there are no indications for the electrolytic capacitors error is...

Page 16: ...152K J 1500 pF 50V C114 VCQYKA1HM472K J AB 0 0047 µF 50V Mylar C115 VCCCPA1HH5R0C J AA 5 pF CH 50V C116 117 VCKYPA1HF203Z J 0 02 µF 50V C118 VCKYPA1HF104Z J 0 1 µF 50V C119 92L1321 002005 J 0 02 µF 50V C120 VCEAZA1CW106M J AC 10 µF 16V Electrolytic C121 92L1321 002005 J 0 02 µF 50V C122 VCKYPA1HF104Z J 0 1 µF 50V C123 VCKYPA1HF203Z J 0 02 µF 50V C124 VCEAZA1CW226M J AC 22 µF 16V Electrolytic C125 ...

Page 17: ... 1 6W R303 304 VRD ST2CD103J J AA 10 kohm 1 6W R305 VRD ST2CD474J J AA 470 kohms 1 6W R306 307 VRD ST2CD222J J AA 2 2 kohms 1 6W R308 311 VRD ST2CD123J J AA 12 kohms 1 6W R312 313 VRD ST2CD222J J AA 2 2 kohms 1 6W R314 315 VRD ST2CD103J J AA 10 kohm 1 6W R316 VRD ST2CD121J J AA 120 ohms 1 6W R317 VRD ST2CD222J J AA 2 2 kohms 1 6W R318 319 VRD ST2CD473J J AA 47 kohms 1 6W R320 321 VRD ST2CD682J J A...

Page 18: ...70338050101 J Damper Gear Ass y 237 92L42838560501 J Bracket Tape Mechanism 238 92L7603 002001 J Ferrite Bar 239 92L3451 000127 J Lead Wire with Lug 1 240 92L45670120101 J Holder Fuse 241 92L7702 003001 J Tape Mechanism Ass y 241 1 92L02104003A 0 J Belt REW FF 241 2 92L02104007A 0 J Belt Main 241 3 92L155 2AM J Head Record Playback 241 4 92L6PA J Head Erase 241 5 M601 92L02103007B 0 J Motor with P...

Page 19: ...5x2 209 207 614 609 601 226 621 208 606x2 606x2 211 238 227 Silicon Grease 603 214 PWB A1 619x2 204 213 204 2 204 1 236 224 223 215 217 219 216 218 220 232 604 203 240x2 203 1 203 2 606x3 611x2 SP501 212 225 221 618 SP502 SP503 201 MIC SP504 611x3 222 613x4 613x4 613x4 613x4 229 TAPE MECHANISM 241 241 1 241 2 241 3 241 4 241 5 M601 241 6 SW601 PWB A5 PWB B PWB A4 Motor M601 REW FF Clutch Flywheel ...

Page 20: ...by any means electronic mechanical photocopying recording or otherwise without prior written permission of the publisher COPYRIGHT 2001 BY SHARP CORPORATION ALL RIGHTS RESERVED A0107 1013DS HA C SHARP CORPORATION AV Systems Group Audio Systems Division Higashihiroshima Hiroshima 739 0192 Japan Printed in Japan EX ...

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