AV250T Service Manual Contents
Contents
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4. J nig A gt 122 y WIE aio SS SEO oe gt 5 GR ry Spare parts list Signal processing Board MATERIAL MATERIAL SPECS amp CODE NAME MODEL 0880230 PT2399 DIP PCS 1 N209 UNIT QTY LOCATION 0880417 IC CD4053BCN DIP PCS 1 N205 0881430 IC CD4053BE DIP PCS 1 205 LM7805 GOLD 0880379 IC PCS 1 N107 SEALED TO 220 MC7805CT 0880247 IC GOLD SEALED PCS 1 N107 220 L7805CV GOLD 0880499 IC PCS 1 N107 SEALED TO 220 0881743 F4558 DIP PCS 4 N201 N204 0882161 IC 24558 DIP PCS 4 N201 N204 0880445 IC 4558C DIP PCS 4 201 204 0880124 NJM4558D DIP PCS 4 201 204 0881393 14558 DIP 5 4 N201 N204 0882223 IC NE5532 DIP PCS 3 N100 N102 0880807 IC PT2315 SOP PCS 1 N200 0880271 IC CD4051 DIP PCS 2 N207 N208 0881428 CD4094BCN DIP PCS 2 N207 N208 0880444 4094 DIP PCS 2 N210 N211 CD11 0880654 IC 16V1000U 20 PCS 2 N210 N211 10x16 5 1 2W220 5 0882338 PCS 2 N210 N211 SHAPED 12 5 15P 40mm2 54mm OUTSIDE 0260030 PCS 1 C130 DISTANCE BETWEEN GLUE CORE 28 4mm METAL 5P140 2 5 OXIDE 0010226 FILM 2PLUG WITH PCS 1 R106 NEEDLE RESISTOR 10P75 2 5 BETWEEN NEEDLE 2PLUG WITH 5100 100 1970064 NETWORK 5 2 s NEEDLE BET
5. 11 1 JE m F F ME exes amp AM WiK I 58 m 10 Mar 2006 1 2 3 4 5 8 L I lt ZB gt T L C gt ele 558 88658 Volume Board schematic amp PCB wiring diagram
6. SHED PCB AV250T RU MATERIAL MATERIALSPECS 8 MODEL CODE we UNIT QTY LOCATION 1 16W 00 5 0090001 5 1 R104 RESISTOR 0603 SMD 1 16W 220 5 0090004 5 1 R209 RESISTOR 0603 0090011 SMD 1 16W 4700 5 PCS 33 R191 R192 R195 R208 RESISTOR0603 R215 R231 SMD AGW 1K 15 R136 R141 R146 R151 0090014 RESISTOR0603 ey PCS 9 R155 R160 R165 R170 R177 SMD 1 16W 1 5K 5 0090016 RESISTOR0603 PCS 2 R122 R114 SMD 1 16W 2 2K 5 0090017 RESISTOR0603 PCS 3 R112 R123 R175 SMD 1116W 47 35 R111 R134 R139 R144 0090019 RESISTORI0603 0 5 11 R149 R153 R158 R163 R174 R185 R101 R108 R117 R125 R131 R133 R137 R138 R142 SMD 4M6V 10K 15 R143 R147 R148 R152 0090023 RESISTOR 0603 7 5 26 R156 R157 R161 R162 R166 R172 R178 R179 R186 R187 R189 R212 R213 R214 SMD 1 16W 15K 5 0090024 PCS 1 R109 RESISTOR 0603 SMD 1 16W 22K 5 0090026 RESISTORI0603 PCS 4 R100 R110 R132 R183 SMD 1 16W 27K 5 0090027 PCS 1 R126 RESISTOR0603 SMD 1 16W 47K 5 0090029 RESISTORI0603 PCS 2 R115 R180 0090034 SMD 1 16W 100K 5 PCS 8 R135 R140 R145 R150 RESISTOR 0603 R154 R159 R164 R167 SMD 1 16W 1 5 0090109 5 1 R210 RESISTOR 0603 SMD 1 16W 3300 5 0090009 5 1 R182 RESISTOR0603 SMD 1 16W 1000 5 0090181 RESISTOR0603 PCS 2 R107 R181 SMD 1 16W 4 3K 5 0090184 RESISTOR0603 PCS 2 R124 R211 SMD 1 16W 180K 5 0090199 PCS 2 R128 R113 RESISTOR
7. 0603 1 16W 470 5 0090208 PCS 4 R129 R130 R116 R169 RESISTOR 0603 SMD 1116W 5 6K 5 0090225 PCS 2 173 8184 RESISTOR 0603 SMD 1116W 75K 5 0090242 PCS 1 2127 RESISTOR 0603 SMD 50V 152 10 0310067 2 C119 C120 0603 OR C105 C142 C143 C144 50V 103 10 145 146 147 148 0310072 PCS 14 0603 149 150 125 126 152 151 SMD 25 104 10 0310594 CAPACIT 4 C102 C107 C108 C155 0603 OR SMD 50V 10 5 0310188 PCS 1 113 0603 OR SMD 50V 30 5 0310191 NPO 0603 PCS 2 103 104 OR SMD 50V 561559 NPO 0310471 PCS 2 116 117 0603 OR SMD 50V 472 10 0310198 PCS 2 122 123 0603 OR SMD 50V 223 10 0310202 PCS 2 128 129 0603 OR SMD 50V 683 10 0310206 5 2 131 132 0603 OR SMD 25V 154 10 0310634 0603 5 2 134 135 OR 1632936 7110 0 5 1 Volume Board MATERIAL MATERIALSPECS 8 MODEL UNIT QTY LOCATION CODE NAME 0881743 IC F4558 DIP PCS 1 108 0882161 AZ4558 DIP PCS 1 108 0880445 4558 DIP PCS 1 108 0880124 IC NJM4558D DIP PCS 1 108 0881393 IC L4558N DIP PCS 1 108 0882223 IC N
8. 5 2 28 56 20 CORDS CONNECTI SHAPED 2100024 22 8 W5 W6 W7 W10 W11 mm CORDS W12 W13 W64 CARBON 1 6W5100 5 0000125 FILM PCS 2 R110 R140 SHAPED 7 5 RESISTOR CARBON 1 6W820Q0 5 0000128 FILM PCS 3 R170 R191 R195 SHAPED 7 5 RESISTOR CARBON 1 6W1K 5 R103 R109 R112 R133 0000129 FILM PCS 6 SHAPED 7 5 R139 R142 RESISTOR CARBON 1 6W2 2K 5 0000132 FILM PCS 2 R115 R145 SHAPED 7 5 RESISTOR CARBON 1 6W1 5K 5 0000131 FILM PCS 2 R129 R159 SHAPED 7 5 RESISTOR CARBON 1 6W4 7Kt5 R161 R167 R114 R144 0000133 FILM PCS 5 SHAPED 7 5 R165 RESISTOR CARBON R101 R131 R162 R163 1 6W10K 5 0000137 FILM PCS 10 R168 R164 R166 R185 SHAPED 7 5 RESISTOR R186 R189 CARBON 1 6W22K 5 R190 R192 R194 R196 0000140 FILM PCS 5 SHAPED 7 5 R188 RESISTOR CARBON 1 6W27K 5 0000141 FILM PCS 1 R171 SHAPED 7 5 RESISTOR CARBON 1 6W33K 5 0000142 FILM PCS 2 R121 R151 SHAPED 7 5 RESISTOR 0000144 FILM RESISTOR 1 6W47K 5 SHAPED 7 5 PCS R104 R134 R169 R193 R197 0000146 CARBON FILM RESISTOR 1 6W100K 5 SHAPED 7 5 PCS R102 R132 R187 0000276 CARBON FILM RESISTOR 1 4W1000 5 SHAPED 10 PCS R120 R122 R150 R152 0000379 CARBON FILM RESISTOR 1 6W6 8K 5 PCS R105 R106 R135 R136 0000452 0000533 CARBON FILM RESISTOR CARBON FILM RESISTOR 1 6W1500 5 SHAPED 7 5 1 2W2200 5 SHAPED R 12
9. AV250T Service Manual Contents chapter One Brief Introduction to Product General description Chapter Two Operating Principle Section One Overall structure Section Two Volume board Section Three Signal processing board Section Four CPU board Section Five Panel control and display circuit Section Six Power amplifier board Section Seven Power board Section Eight Video board Chapter Three Servicing Process 1 No output for Karaoke 2 Power supply not connected 3 screen display OSD 4 No output Schematic 8 PCB wiring diagram Spare parts list Chapter One Brief Introduction to Product General Description AV110T is a5 1CH audio power amplifier for home theatre usage with the main features and functions shown as follows 1 Two way audio signal input VCD DVD 2 With 5 1CH input terminal capable of connection with AC 3 DTS decode output signal 3 One way subwoofer signal line output capable of connecting with active subwoofer speaker 4 Automatically signal search when power 5 6CH digital volume control and separate channel level adjustment 6 Three sound field modes Hi Fi Standard and Cyber Logic 7 Six preset EQ modes multi band electronic equalization adjustment snd scene surround function 8 Save Call of user set parameter 9 Digital Karaoke with microphone volume echo and delay adjustment 10 Auto mute function 11 Dynamic display screen multiple spectrum display mode
10. R109 0000301 CARBON FILM RESISTOR 1 4W47K 5 SHAPED 10 PCS R118 R119 R120 0000436 CARBON FILM RESISTOR 1 4W2K 5 SHAPED 10 PCS R121 R122 0000302 CARBON FILM RESISTOR 1 4W51K 5 SHAPED 10 PCS R116 R117 0000305 CARBON FILM 1 4W100K 5 SHAPED 10 PCS R108 RESISTOR 0000476 CARBON FILM RESISTOR 1 6W56K 5 SHAPED 7 5 PCS R110 0000499 CARBON FILM RESISTOR 1W4 7 0 5 SHAPED R 15x9 PCS R111 R115 0000622 CARBON FILM RESISTOR 2W22 0 5 SHAPED R 20 8 PCS R100 0260028 CD CD11 16V220U 20 6x 12 2 5 PCS 113 114 0260039 CD11 25V47U 20 5x1 1 2 PCS 115 0260452 CD11 35V220U 20 8 14 3 5 5 110 0260572 CD293 63V15000u 20 35x70 10 PCS 108 109 0200138 PORCELAI N CAPACITO R 50V 104 20 5mm PCS 122 0200174 0200338 PORCELAI N CAPACITO R CERAMIC CAPACITO R 50V 103 10 2 5 7 400VAC 472 20 2E4 10mm PCS PCS 121 112 123 126 102 0210022 CAPACITO R 100 223 5 5mm PCS 100 101 105 111 0210029 R 100 104 5 7mm PCS 106 107 116 120 0210031 100V 224 10 8mm PCS
11. 1 Power on delay attracting protection circuit The working of circuit is unstable when power on and the generated percussive current does great harm to speaker and power amplifying circuit so delay attracting protection circuit is set This circuit is divided into two steps 1 C L R The working process is a 22V voltage is achieved after AC outputted by transformer being rectified and filtered by VD113 C110 and then charges C115 through R108 to make VD111 struck through reversely and make V105 and V104 in phase on to finally make 100 attract to reach delay effect Surround left and right channels perform anti percussion protection when power on after machine system resets pin 33 of CPU outputs a high level to pin 9 14 of LM1876 through R164 to make LM1876 output mute After delay start up of machine succeeds pin 33 of CPU converses to low level immediately and outputs normally through SL SR channel 2 Central point over voltage protection An over voltage sampling resistor is connected to the output terminal of each channel L channel is R116 R channel is R117 C is R118 SR and SL channels are R119 and R120 respectively Only when one channel s central point voltage is above 3 5V or below 3 5V V101 or V102 is to make their C pole voltage decrease then V103 on relay disconnected and protection circuit start up finally Over voltage Relay When above gt V101 sampling resistor L 7 C pole discon
12. C103 C104 CAPACITO R TERYLEN E 100V 224 5 0210213 PCS 103 104 R INDUCTO 0 7UH 0410007 PCS 1100 1101 R COIL 5 0 8 8 0 11 5 0570004 DIODE 1 4004 PCS 0113 0570006 DIODE 1 4148 PCS VD112 VD108 VD110 0570020 DIODE 1 5404 PCS VD100 VD107 VOLTAGE 05800069 REGULAT 5 1V 1 2W PCS 0111 OR DIODE 0780032 TRIODE 9014C PCS V100 V101 V102 V105 9015 200 600 0780033 TRIODE PCS V103 92 0780138 TRIODE 80500 PCS 104 JH1806 012 3H1 1250025 RELAY PCS 100 121 DC12V FLAT 4P60 2 5 2PLUG 2120535 PCS XP7 CABLE WITH NEEDLE FLAT 2121040 9P60 3 96 1PLUG PCS 1940037 SOCKET 3 96 5 XS4 1940074 SOCKET 2P7 92mm PCS XS1 XS3 SPEAKER 2010003 WP4 10A PCS XL100 S CORD SPEAKER 2010004 WP6 10A PCS XL101 S CORD 2300005 FUSE T6 3AL 250V PCS FL100 2300008 FUSE T8AL 250V PCS FL101 FL102 FUSE 3020402 BLX 2 PCS FL100 HOLDER FUSE 3870057 0 PCS FL101 FL102 HOLDER 5 AV100 OUTPUT 3540076 HIEDED PCS TERMINAL PIECE GROUNDI 3870591 100 5 NG PIECE STICK TO FL101 GLUE 5180263 T8AL 250V PCS BESIDE FL102 STICKER COVER T6 3AL250V GLUE STICK BESIDE FL100 5180388 T6 3AL250V 18x3 PCS gt STICKER COVER T4AL250V 1564105 PCB 5100 5 PCS
13. CAPACIT C153 OR TERYLEN C102 E 100V 473 5 02102209 5 6 103 116 131 143 SHAPED 5 153 OR TERYLEN E 100 103 10 02101599 PCS 1 C145 CAPACIT SHAPED 5mm OR TERYLEN E 100 103 5 02102239 PCS 1 C145 CAPACIT SHAPED 5mm OR METAL POLYEST CL21X100V334K 02101419 ER FILM PCS 2 125 126 CAPACIT OR VOLTAGE 05800459 REGULAT 6 8V 1 2W PCS 2 VD100 VD101 OR DIODE VOLTAGE 05800099 REGULAT 9 1V 1 2W PCS 1 0112 OR 07801389 TRIODE 80500 1 106 1564053 2110 0 5 1 Power Amplifer Board MATERIAL MATERIAL SPECS amp UNIT QTY LOCATION CODE NAME MODEL CONNECTI W16 W18 W27 W40 W42 0 6 SHAPED 2100003 ON 5 13 W43 W54 W55 W61 CORDS W72 W76 W77 W78 W8 W9 W15 W21 W24 0 6 SHAPED W36 W41 W45 W46 W48 tae 10 M 19 W51 W57 W63 W65 W6 mm 4 CORDS 9 W71 W73 W74 W80 PONNECT 506 SHAPED W3 W20 W35 W59 W62 2100006 j PCS 7 12 5mm VV66 VV70 CORDS 6 SHAPED VV2 VV14 VV19 VV26 VV50 2100007 5 10 15mm W53 W67 W79 W81 W82 CORDS CONNECTI SHAPED W1 W33 W47 W49 W60 2100010 PCS 6 5mm 68 CORDS CONNECTI SHAPED 2100016 5 4 IW39 W52 W58 W75 18mm CORDS CONNECTI SHAPED 2100017
14. ae L Bass control input output pin of L channel ATN R Bass control input output pin of R channel 16 RFOUT R channel output 17 LFOUT L channel output 18 DGND Digital 19 DATA Control data of sequence transmission DATA 20 LCK Clock input of sequence transmission 8 10 NC Not connected 2 3 2 Flow chart of Karaoke signal When the microphone is inserted MIC signal is sent via MIC to the transmittal circuit combined by 201 for amplification Amplified MIC signal gives CPU a MIC identification signal after N202A amplification followed by VD201 rectification and filtering control triode V200 CPU sends PKM signal which is of low level causing cutoff of triode V103 V105 and enabling output of MIC signals another way reaches pin 6 and 11 of PT2315 after 219 222 coupling outputs from pin 16 17 after internal volume and tone control mixed into one way and sent to N202B and then reversely send to N203B for amplification Signals amplified by N203B are divided into two ways one way is directly outputted and the other way is outputted from pin 14 after being coupled by R222 C247 to PT2399 for internal delayed echo adjustment reversed by N204B and outputted by mixing with karaoke signal While OK R is outputted from pin 14 after being gated by N205 and superposed to L R channel In this circuit the bass boost network made up of triode V201 connected to the negative terminal of N202B is primarily for bass boost of 75HZ low frequency s
15. 121 122 128 129 02101489 5 10 R SHAPED 5mm 143 144 209 212 ITERYLENE 100V 562 10 121 122 128 129 02102209 5 10 R SHAPED 5mm 143 144 209 212 ITERYLENE 100V 562 5 02101579 CAPACITO 5 4 225 226 242 243 R SHAPED 5mm ITERYLENE CL21X100V224 02102219 CAPACITO PCS 4 225 226 242 243 C5BD R METAL POLYESTE CL21X 100V 02101049 R FILM PCS 2 213 214 104 C5 R METAL POLYESTE 02101459 R FILM1N4004 PCS 2 232 233 R 05700049 DIODE 1N4148 PCS 2 VD106 VD107 VD201 VD203 VD108 0570006 DIODE 5 1V 1 2W PCS 12 D100 VD105 VD109 0111 VOLTAGE 05800069 REGULAT 9 1V 1 2W PCS 1 VD202 OR DIODE VOLTAGE 05800099 REGULAT 2N5401 PCS 1 0200 DIODE 07800259 TRIODE 9014C PCS 3 103 107 108 07800329 TRIODE 80500 5 4 102 200 201 110 105 101 104 100 07801389 TRIODE 3110 2 PCS 5 409 01564101 1 CPU Board MATERIAL MATERIALISPECS amp UNIT QTY LOCATION CODE NAME MODEL RESISTOR 1 6W 4 7K 5 0100008 NETWOR gp PCS 1 RR100 1000 40 INDUCTO 0390168 R 0410 SHAPED PCS 1 L100 12 5 BEADSRH 357508 0390353 5 1 L101 INDUCTO SHAPED 12 5mm R CARBON 1 4 4700 5 0000279 FILM 5 2 R118 R119 SHAPED 10 RESISTOR CD11 111 112 114 115 0260019 CD 16V10U 20
16. R140 RESISTOR CARBON 00000439 FILM 1 6W15K 5 PCS 4 R232 R254 R226 R230 RESISTOR CARBON 00000449 FILM 1 6W18K 5 PCS 3 261 8121 8123 RESISTOR CARBON R202 R129 R218 R120 00000459 FILM 1 6W20K 5 PCS 5 RESISTOR CARBON 00000469 FILM 1 6W22K 5 PCS 4 R284 R132 R133 R134 RESISTOR CARBON 00000489 FILM 1 6W27K 5 PCS 1 223 RESISTOR CARBON 00000499 FILM 1 16W30K 5 PCS 2 260 124 RESISTOR CARBON 00000509 FILM 1 6W33K 5 PCS 1 R269 RESISTOR CARBON 00000519 FILM 1 6W39K 5 PCS 4 R246 R200 R142 R145 RESISTOR CARBON 00000589 FILM 1 6W82K 5 PCS 2 R17 R122 RESISTOR 00000529 FILM RESISTOR 1 6W47K 5 PCS R100 R103 R241 R231 R104 R105 00000549 CARBON FILM RESISTOR 1 6W56K 5 PCS R258 00000559 CARBON FILM RESISTOR 1 6W62K 5 PCS R256 00000599 CARBON FILM RESISTOR 1 6W100K 5 PCS R115 R116 R228 R229 R118 00000609 00000629 CARBON FILM RESISTOR CARBON FILM RESISTOR 1 6W120K 5 1 6W150K 5 PCS PCS R257 R244 00000659 00000669 CARBON FILM RESISTOR CARBON FILM RESISTOR 1 6W200K 5 1 6W220K 5 PCS PCS R233 R234 R235 R240 00001759 CARBON FILM RESISTOR 1 4W1000 5 PCS R204 00003459 CARBON FILM RESISTOR 1 6W36K 5 PCS R255 00003519 CARBON FILM RESISTOR 1 6W43K 5 PCS R262 R101 R102 0
17. and EQ setup available 2 2 2 Control circuit Pin 23 26 27 of CPU N100 output data PVST and clock signals send to pin 39 40 41 of M62446 control pin 1 2 3 4 of M62446 output control level so as to select input signal and spectrum sampling signal It is worth noting that PVST signal is a latch control signal When data and clock of CPU are sent to M62446 an identification signal will be added indicating that this signal can only be used by M62446 while other IC of ZC bus cannot use current data and clock signal 2 2 3 Frequency spectrum sampling circuit Only S C S SR S SL SW signals are sampled during frequency spectrum sampling in 250 and added to pin 14 of N103 a 150K sampling resistor Another S C cyber logic signal is added to pin 1 of 103 called S C 5 1CH and of M62446 select sampling signals When cyber logic is selected the control signal of 5 1CH is of low level while pin 9 11 of N103 is of low level According to the truth table it is known that outputs are 20 Sampling signal is grounded while LR T is of H level Select Y1 S C signal is outputted from pin 15 of N103 to N108B adding to OK R signal for the amplification of frequency spectrum signal and then sent to frequency point gating and auto search circuits 20 2 2 4 Tuning function The tuning function directly controls tuner and receives audio frequency signal mainly via CPU and then outputs after amplification via po
18. board 1 L R channel power amplifying circuit L R channel power amplifying circuit of AV250T RU is composed of discrete components with the composed frame diagram shown as follows Take L channel as an example Composite power AC negative amplifying V132 V112 feedback R121 R108 C105 Voltage Differential amplifying Temperature amplifying stage stage compensation stage V102 V103 V105 V106 Composite power amplifying V133 V113 Mirror image constant source V104 V107 VD102 VD103 L channel signal is sent to pole of differential amplifying stage V102 after being coupled by R101 R103 and C101 V102 and V103 compose single ended input output differential amplifying circuit Sound signal outputs from pole C of V102 to pole B of voltage amplifying stage V105 and then outputs to composite power amplifying stage after voltage amplifying V104 V107 VD102 and VD103 compose mirror image constant source circuit VD102 VD103 provide V104 V107 with constant base electrode current Emitter resistor of V104 determines working current of differential amplifying stage and emitter resistor of V107 determines working current of voltage amplifying stage V132 and V112 compose multiple unit tube amplifying to supply strong current amplifying capacity for final stage of power amplifier which composes waveform positive half cycle amplifying 133 and V113 compose waveform negative half cycle amplifying an
19. control of overall CPU only L R channel output is available to M62446 3 Cyber Logic Pin 9 10 of electronic switch N101 CD4052 select a group of analog L R channel input signals according to the truth table L R signals are outputted from pin 13 3 via the internal electronic switch of N101 and divided into two ways One way is respectively sent into pin 13 15 of M62446 for electronic volume and tone adjustment The other way produces SW S SR S SL and S C signals via buffer adder subtractor and low pass filter S C S SR S SL signals are sent to pin 12 2 5 of N102 N102 select Cyber Logic signal input see CD4053 truth table from Cyber Logic and 5 1Ch signals outputs C SR SL signals from pin 14 15 4 and sends into pin 11 8 9 of M62446 for volume adjustment Still another way of SW signal directly sends to pin 6 of M62446 after being outputted from N107A 5 1CH signal sent into M62446 is outputted from pin 31 36 after volume and tone adjustment and then outputted to signal board by XS20 power distributor The relation between sound sources in input circuit and sound processing modes is as the following figure Only L R channel output Sound field and EQ setup invalid Two analog Only L R SW channel input Standard output Concert hall modes sound field and EQ setup available Press INPUT button to select 6CH output Theatre circularly sound field and EQ setup available 5 1 input 6CH output Theatre mode sound field
20. inputs from pin 7 of N103B and then is sent to pin 16 of CPU via VD103 V101 R109 and R107 When N103B inputs a high level VD103 is in reverse cut off status B pole of switch tube V101 is high level and is in conducting status then gets an about 5V high level signal input to CPU after VD101 s stabilization and stop searching When the output end of N103B outputs a low level VD103 is in conducting status B pole of switching tube V101 is low level and is in cut off status and then CPU detects the low level no signal input working principles are as follows After starting up under CPU internal program s control a data signal is outputted via pin 23 to M62446 and then M62446 scans each input port of N101 N102 and N103 by emitting high and low levels When the input ports have no signal input it automatically becomes standby status When any of ports has signal input channel paths of input N101 N102 and N103 has A C signal which is amplified and limited level by N108B and N103A of CPU board then compares with pin 5 of N103B and gets plus minus level close to supply power The co phase voltage of N103B is about 0 1V After the direct current voltage is over 0 1V the output end of N103B outputs low level is close to negative power voltage VD103 positive bias conducts switch tube V101 59014 stops emitter outputs a low level to pin 16 of CPU which by controlling IC M62446 makes search level lock on the port through whi
21. 00 is complete and good Yes Check the primary coil resistance numerical No value of transformer Yes Check whether the secondary voltage of transformer is normal Whether the input and output of three terminal Whether the secondary fuse 15 voltage regulator are complete and good abnormal Whether power supply Whether the output voltage of pin 40 of CPU voltage of rectifier tube is normal is normal In most cases primary short circuit of transformer will burn out this fuse 1 primary internal short circuit of transformer occurs the resistance numerical value will decrease fuse will be burnt and power supply will not be connected 2 The primary internal circuit opening of transformer leads to disconnection of power supply The short circuit and circuit opening inside the transformer secondary coil lead to abnormal output of secondary voltage Whether the control panel IC and display screen voltage is normal 3 on screen display OSD Check whether the filament voltage of display screen is normal Note The abnormality of the secondary output Whether the power of voltage of transformer control panel IC is may probably cause no normal OSD Yes Check whether the data line between CPU and control panel drive IC and clock line signals are normal Note If display screen has air leakage it will cause no OSD and now
22. 0003609 CARBON FILM RESISTOR 1 6W 7 5 5 PCS R108 00006239 CARBON FILM RESISTOR 1 2W2200 5 PCS R263 00102289 METAL OXIDE FILM RESISTOR 1 4W10 5 PCS R170 R171 CD11 02600019 16V22U 20 PCS 2 119 115 5x11 5 CD11 02600029 16V47U 20 PCS 8 124 125 202 207 5x11 5 CD11 02601819 16V220U 20 PCS 1 C134 6x12 C5 CD11 02601889 CD 16V100U 20 PCS 142 208 6x12 5 2 CD11 02603909 50 0 471 20 5 C240 5x11C5 1 CD11 131 100 101 132 02604379 16V4 7U 20 PCS 10 215 217 219 221 5x11C5 252 02604389 50V 47P 10 PCS 8 113 114 118 245 SHAPED 5mm C249 PORCELAI 02003069 N 5 6 103 108 CAPACITO SHAPED 5mm R PORCELAI N 50V 103 10 CAPACITO SHAPED 5mm 29 R PORCELAI 02003109 N 50V 10 10 PCS 6 237 239 135 138 CAPACITO SHAPED 5mm 137 R PORCELAI N 50V561 10 CAPACITO SHAPED 5mm Wa R PORCELAI 02003299 22 12 22 5 2 250 251 SHAPED 5mm R PORCELAI N 100V 683 10 02003309 5 1 C200 CAPACITO SHAPED 5mm R ITERYLENE 100V392 10 02100689 CAPACITO C5 PCS 3 227 228 231 R ITERYLENE 100V 473 10 02101439 CAPACITO PCS 1 C234 R SHAPED 5mm ITERYLENE 100V 473 5
23. 01 is cut off and SW signal is superposed to L R channel signal The bass enhancer of AV250T can be divided into three steps This principle is to change the volume of bass enhancer by changing the SW output volume of M62446 2 3 4 Mixing and amplification circuit of 5 1 signal and karaoke signal When L R channel signal of 5 1 signal is superposed with SW signal and amplified by N101B N100B it is sent to the reverse phase of N101A N100A Meanwhile OK R OK L signals are also respectively added to the reverse phases of N101A N100A After mixing and amplification by N100A N101A they are respectively outputted from pin 1 of N100A N101A to power amplification circuit for power amplification Meanwhile the C 1 signal sent by volume board is added to the reverse phase of pin 6 of N102B and added to the reverse phase of N102A after amplification Now C1 1 signal after electronic echo processing is also added to the reverse phase of N102A and sent to power amplification circuit after mixing and amplification SR 1 SL 1 of another volume board is also added to the reverse phase of N103B and N104B for amplification and then sent to N103A and N104A for further amplification and later sent to power amplification circuit One way of 5 1 signal after being mixed and amplified is sent to power amplification circuit passing through XS9 and the other way forms DIST distortion error detecting signal signal passing through R111 R113 R142 R145 VD100 V
24. 112 R113 R116 R120 00000529 1 6W47K 5 PCS 19 RESISTO R117 R132 R121 R144 R R140 R152 R174 R178 CARBON FILM 00000549 1 6W56K 5 PCS 3 R137 R138 R195 RESISTO R CARBON FILM 00000569 1 6W68K 5 PCS 1 R169 RESISTO R CARBON FILM 00000579 1 6W75K 5 PCS 1 R170 RESISTO R CARBON FILM R139 R157 R162 R167 00000599 1 6W100K 5 PCS 10 RESISTO R191 R196 R CARBON 00000629 1 6W150K 5 PCS 4 R133 R134 R135 R136 FILM RESISTO R CARBON 1 2 220 5 FILM 00006239 PCS 2 R129 R131 RESISTO R CD11 101 104 107 108 02600029 16V47U 20 PCS 10 115 132 142 147 5x11 C5 152 154 111 117 118 119 CD11 120 121 122 129 02604389 16V4 7U 20 PCS 15 130 133 134 135 5 11 5 138 136 137 PORCELA IN 50V 22P 10 02003059 PCS 1 114 CAPACIT SHAPED 5mm OR PORCELA IN 50V 101 10 109 110 112 139 02003079 5 6 CAPACIT SHAPED 5mm 140 141 OR PORCELA IN 50V 221 10 02003089 5 3 105 106 113 SHAPED 5mm OR PORCELA IN 50V 103 10 02003109 5 2 144 148 CAPACIT SHAPED 5mm OR PORCELA IN 50V 822 10 02003149 5 2 123 128 CAPACIT SHAPED 5mm OR TERYLEN 100V392 10 C5 E 02101439 PCS 1 C146 CAPACIT OR TERYLEN E 100V 153 10 02101449 PCS 2 124 127 CAPACIT 5 100 473 10 C102 02101489 E SHAPED 5mm PCS 6 103 116 131 143
25. 27 CD 16V100U 20 6x PCS 1 TC101 12 2 5 CD11 0260028 CD 16V220U 20 6x PCS 2 TTC103 TC104 12 2 5 0880271 IC CD4051 DIP PCS 1 N101 0881428 IC CD4051BE DIP PCS 1 N101 0780043 ITRIODE PSA1015 PCS 1 101 1940006 SOCKET 6 2 5mm PCS 1 KS101 1910239 TERMINAL V 4 44 C8 40 1 XC101 1564076 C210T 0 PCS 1 Front Panel Board MATERIAL MATERIALSPECS 8 GN NAME MODEL SURFACE 3004192 IAV250T SILVERY PCS 1 CASING LIGHT 250 3071946 CONDUCT TRANSPARENT PCS 1 POWER SWITCH RING1 WHITE LIGHT 250 3071947 CONDUCT TRANSPARENT PCS 1 Q PLAY RING2 WHITE LIGHT 250 TO BUTTON 3071948 CONDUCT TRANSPARENT PCS 2 BRACKET STRIP WHITE BUTTON 3071949 AV250T PCS 1 BRACKET 3871823 PREFORM 250 5 SOCKET PANEL 3071950 DECORATI ON GLASS 250 GLASS FACE PCS 3871821 ALUMINU M DECORATI ON BOARD 250 SILVERY PCS 3871822 ALUMINU M DECORATI ON STRIP 250 SILVERY PCS STICK TO CONDUCT STRIP LIGHT 3110527 3110380 3029205 ALUMINU M ALLOY POWER BUTTON POWER BUTTON DECORATI ON CASING POWER BUTTON 168 SILVERY WHITE AV138 SILVERY WHITE AV138 PCS PCS PCS 4000048 SELF TAP PING SCREW PB 3x8 COLORFUL ZINC PCS 7PCS PANEL CONTROL PANEL 2 5 FOR PANEL POWER SWITCH BOARD FOR 4000120 SE
26. 5x1 PCS 5 C139 1 2 CD11 0260025 CD 16V47U 20 5x1 PCS 1 100 12 CD11 0260049 CD 50V0 22U 20 5x PCS 1 C138 11 2 CD11 118 121 124 127 0260067 CD 50V2 2U 20 5x1 PCS 8 42 130 133 136 109 CD110 0260096 CD 16V100U 20 6x PCS 2 140 141 12 2 5 CD11 0260127 CD 16V4 7U 20 5x1 PCS 2 110 106 12 METAL CL21X 63V 104 POLYEST 5 5 0210111 ER FILM PCS 1 137 VD102 VD103 VD108 VD109 VD110 VD111 0570006 DIODE _ 4148 PCS 13 112 113 114 VD115 VD116 VD118 0119 VOLTAGE 05800019 REGULAT 3 3V 1 2W PCS 1 V0117 OR DIODE VOLTAGE 05800059 REGULAT 4 7V 1 2W PCS 1 0101 OR DIODE VOLTAGE 05800459 REGULAT 6 8V 1 2W PCS 2 MV0106 V0107 OR DIODE 0780025 TRIODE 2 5401 PCS 1 103 0780032 TRIODE 9014C PCS 5 100 0880013 LM324N DIP PCS 2 105 106 0880271 IC CD4051 DIP PCS 2 104 108 0881428 IC CD4051BE DIP PCS 2 104 108 0880664 C 24002 DIP PCS 1 101 0881743 IC F4558 DIP PCS 3 N102 N103 N107 0882161 IC 74558 DIP PCS 3 N102 N103 N107 0880445 IC 4558C DIP PCS 3 N102 N103 N107 0880124 IC NJM4558D DIP PCS 3 N102 N103 N107 0881393 IC IL4558N DIP PCS 3 N102 N103 N107 CERAMIC 0970002 5 12 0 2 5 1 6100 OR SOFTWAR E 0890277 CPU250T RU 0 PCS 1 M CPU DUAL 40P DIP 1850005 LINE IC PCS 1 M100 SOCKET eee SEMI FINI 7228 1 SMD
27. 5x8 PCS PCS R113 R116 R143 R146 R117 R125 R147 R155 0000495 0000556 CARBON FILM RESISTOR CARBON FILM RESISTOR 1 6W4 3K 5 SHAPED 7 5 1 6W47045 SHAPED 7 5 PCS PCS R128 R130 R158 R160 R107 R108 R137 R138 0040069 CEMENT RESISTOR 7 0 250 5 SQM SHAPED R 10x5 PCS R126 R127 R156 R157 0010321 METAL OXIDE FILM RESISTOR 1 2W33K 5 SHAPED 12 5 PCS R111 R141 0010210 METAL OXIDE FILM RESISTOR BW47 5 SHAPED R 20x8 PCS R184 0010268 METAL OXIDE FILM RESISTOR 3W220 5 SHAPED R 20x8 PCS R183 0260389 CD CD1150V0 22U 20 5 11 5 124 103 109 0260036 CD11 25V10U 20 5x11 2 PCS 101 111 102 CD11 121 122 125 104 0260021 CD 16V22U 20 PCS 5 ITC110 5x11 2 CD11 0260027 CD 16V100U 20 PCS 4 105 115 148 149 6 12 2 5 CD11 0260063 CD 50V1U 20 PCS 2 110 120 5x11 2 CD11 100V47U 0260302 CD PCS 4 103 107 113 117 20298 15 3 5 LUA 35V4700U 0260447 CD PCS 2 C141 C142 20 18 35 7 5 CD11 0260234 CD 35V4700U 20 PCS 2 141 142 19 35 7 5 CD11 100V10U 0260465 CD 5 1 159 20 6 3 X11 2 5 CD11K35V220U 0260487 CD PCS 2 146 147 2090 8 16 3 5 PORCELAI N 50V 22P 10 PCS 2 160 163 2 5 0200018 PORCEL
28. 7 CORDS 20mm 0 6 SHAPED PCS W79 W81 W83 00000029 CARBON FILM RESISTOR 1 6W10 5 PCS R259 00000119 CARBON FILM RESISTOR 1 6W2200 5 PCS R158 R161 00000139 CARBON FILM RESISTOR 1 6W3300 5 PCS R242 00000179 CARBON FILM RESISTOR 1 6W5100 5 PCS R236 R273 00000189 CARBON FILM RESISTOR 1 6W5600 5 PCS R111 R113 00000199 CARBON FILM RESISTOR 1 6W6800 5 PCS R239 R274 00000229 CARBON FILM RESISTOR 1 6W1K 5 PCS R110 R109 R209 R211 00000269 CARBON FILM RESISTOR 1 6W2K 5 PCS R248 R252 R213 R215 00000279 CARBON FILM RESISTOR 1 6W2 2K 5 PCS R151 R152 00000309 CARBON FILM RESISTOR 1 6W3 3K 5 PCS R272 00000329 CARBON FILM RESISTOR 1 6W3 9K 5 PCS R247 00000349 CARBON FILM RESISTOR 1 6W4 7K 5 PCS R153 R169 R264 R167 00000359 CARBON FILM RESISTOR 1 6W 5 1 5 PCS R207 00000369 FILM 1 16W5 6K 5 PCS 1 216 RESISTOR CARBON 00000379 FILM 1 6W6 8K 5 PCS 1 270 RESISTOR CARBON 00000389 FILM 1 6W8 2K 5 PCS 1 266 RESISTOR KARGON R139 R220 R222 R238 00000409 FILM 1 6 10 5 5 13 R162 R163 R224 R225 R227 CARBON 00000419 FILM 1 6W12K 5 PCS 4 R271 R221 R137
29. AI N 50V 221 10 0200066 PCS 2 104 114 2 5 R PORCELAI N 500V33P 10 0200333 NPO SHAPED PCS 2 108 118 R ITERYLENE 109 119 127 128 100V 473 10 0210147 L 5 12 139 140 150 151 R 161 162 164 165 ITERYLENE 109 119 127 128 100 473 5 0210025 CAPAGITO L PCS 12 139 140 150 151 R 161 162 164 165 0570006 DIODE 1N4148 PCS 8 MVD101 vD107 VD115 MVD111 VD112 VD113 0570020 DIODE 1N5404 PCS 4 VD114 105 115 120 130 0780025 2 5401 5 5 137 102 104 106 107 0780026 TRIODE 2N5551 5 12 114 117 119 121 V122 V129 0780138 TRIODE 80500 PCS 4 M101 V116 V131 V136 0780070 TRIODE 25 1964 PCS 2 133 V135 0780255 TRIODE 254940 PCS 2 133 V135 0780257 TRIODE KSA940 PCS 2 133 135 0780072 TRIODE 25 5248 PCS 2 MV132 V134 0780021 TRIODE 2SC2073 PCS 2 MV132 V134 0780258 TRIODE 5 2073 PCS 2 MV132 V134 0780097 TRIODE 25 52008 PCS 2 112 127 0780071 TRIODE 25 52000 PCS 2 112 127 0780096 TRIODE 25 1943 PCS 2 MV113 V128 0780069 TRIODE 2SA19430 PCS 2 MV113 V128 0882646 IC 5 1 101 0880131 IC 5 1 101 SEALED 220 LM7812 GOLD 0880380 IC PCS 1 N101 SEALED TO 220 UA7812C GOLD 0881418 SEALED TO PCS 1 N101 220 7812 0880324 IC GOLD SEALED PC
30. D104 which will be added to CPU for automatic gain adjustment so as to control volume output Section Four CPU board 2 4 1 CPU control unit N100 the overall CPU is the overall control center inputting all kinds of control instructions to controlled circuits to achieve all kinds of control functions It adopts 5V supply with pin 40 as its supply pin Pin 18 and pin 19 connect externally with 12M crystal oscillator to provide working clock frequency for itself Pin 9 is its reset pin When starting 5V charges C106 via R100 The voltage of two ends of capacitance cannot be mutated thus B pole of triode 100 is low level that is V100 conduction gives a high level reset signal to CPU When capacitance C106 finishes charge V100 stops and then reset finishes The form of this reset circuit is to reset high level and keep low level When the machine is working the static information of Power on logo on screen and Chinese characters are stored in CPU internal static memory N101 a status memory can record the current working status of machine when powering off and show the status when next time power on avoiding users to re adjust The sound field mode set by users is also stored in it and can be called when necessary 2 4 2 Detect input signal and automatically search circuit DISPLAY signal from volume board is sent to N103A to amplify and limit level and then sent to inverse end of voltage comparator N103B after capacitance coupling It
31. E5532 DIP PCS 104 105 107 0880417 CD4053BCN DIP PCS 2 N103 N102 0881430 IC CD4053BE DIP PCS 2 N103 N102 0881429 CD4052BE DIP PCS 1 101 0880443 IC CD4052BCN DIP PCS 1 01 M62446AFP 0881380 PCS 1 N106 SOP 400UH 10 INDUCTO 0390425 0307 SHAPED pcs 4 101 42 5 TERMINA 6 8 4 13 5 1910117 1 Kc402 SOCKET TERMINA 1910118 4 8 4 13 5 1 XC101 65P 1 2 CABLE ZM 1940072 DUAL LINE PCS 1 X519 STRAIGHT PLUG FLAT 6 140 2 5 2PLUG 2120325 PCS 1 101 CABLE WITH NEEDLE 1940029 SOCKET 2 5mm PCS 1 X522 1940030 SOCKET 2 5mm PCS 1 X520 GROUNDI 3870591 100 2 SEMI FINI 2110 0 5447608 SHED 1 AV110T RU PCB MATERIAL MATERIAL UNIT QTY LOCATION CODE SPECS 8 MODEL CONNECT 0 6 SHAPED 2100003 ION W1 W73 7 5mm CORDS CARBON 00000099 4 1 6W100 2 5 PCS 1 63 8164 8165 RESISTO R CARBON R103 R106 R107 R110 FILM R111 R114 R115 R118 00000229 1 6W1K 5 PCS 16 RESISTO R119 R122 R124 R126 R R197 R130 R198 CARBON FILM R141 R145 R149 R150 00000469 1 6W22K 5 PCS 8 RESISTO R153 R154 R155 R156 R CARBON FILM 00000489 1 6W27K 5 PCS 3 R143 R147 R168 RESISTO R CARBON FILM 00000499 1 6W30K 5 PCS 1 R148 RESISTO R CARBON FILM 00000509 1 6W33K 5 PCS 2 R142 R146 RESISTO R CARBON R104 R105 R108 R109 FILM R
32. LF TAP PING SCREW PB 3x10 COLORFUL ZINC PCS 2PCS FOR POWER SWITCH PANEL 3PCS FOR PANEL MIC HOLDER PREFORM 5447833 SEMI FINI SHED PCB 6250 0 250 5 5447834 SEMI FINI SHED PCB D250T 0 250 5 5447835 SEMI FINI SHED PCB 9250T 0 250 5 Power Board MATERIAL CODE MATERIAL NAME SPECS 8 MODEL UNIT QTY LOCATION 2100003 CORDS 0 6 7 5mm SHAPED PCS W14 W16 W17 W22 2100004 CORDS 0 6 10mm SHAPED PCS 10 W7 W8 W10 W11 W1 W2 L102 L103 L104 W13 2100007 CORDS 0 6 15mm SHAPED PCS W5 W12 W15 W4 W9 19 2100008 CORDS 0 6 SHAPED 6mm PCS W20 W21 2100017 0000129 CORDS CARBON FILM RESISTOR 0 6 20mm 1 6W1K 5 SHAPED 7 5 SHAPED PCS PCS W18 W3 W6 R101 R102 0000137 0000144 CARBON FILM RESISTOR CARBON FILM RESISTOR 1 6W10K 5 SHAPED 7 5 1 6W47K 5 SHAPED 7 5 PCS PCS R104 R105 R103 0000146 CARBON FILM RESISTOR 1 6W100K 5 SHAPED 7 5 PCS R107 0000289 CARBON FILM RESISTOR 1 4W4 7K 5 SHAPED 10 PCS R106 0000294 CARBON FILM RESISTOR 1 4W10K 5 SHAPED 10 PCS
33. R 7912 HEAT RADIATION BOARD 4PCS SELF TAPPING SCREW POWER PIPE FOR SCREW 4450012 3x7 2x0 5 PCS 7 1PC FOR TAPPING SPACER SCREW CD1875 2PCS FOR TAPPING SCREW TDA2052 4PCS FOR SELF TAPPING SCREW POWER PIPE SPRING 4490001 7 1PC FOR TAPPING SPACER SCREW CD1875 2PCS FOR TAPPING SCREW TDA2052 INSULATIO 1PC FOR 5230395 SPACERQ3x6x3 5 3 CD1875 SELF TAPPING CASING SCREW MIC 4PCS FOR POWER 5230979 28 22 0 1 5 4 SPACER RADIATOR 1PC FOR MIGA CD1875 LARGE HEAT 5230928 18x13x0 1 PCS 3 RADIATOR 2PCS FOR SPACER ITDA2052 LARGE HEAT RADIATOR SOFT 80x12x1 5 FLAT CABLE XP9 5232006 SPONGE SINGLE SIDED PCS 1 XP13 HEAT RADIATOR SPACER SOFT 1564051 PCB 4320T 0 PCS 1 Video Board MATERIAL MATERIALSPECS amp UNIT QTY LOCATION CODE NAME MODEL CARBON 1 6W22Q0 5 0000120 FILM PCS 1 R103 SHAPED 7 5 RESISTOR CARBON 1 6W1000 5 0000122 FILM PCS 4 R101 R102 R104 R105 SHAPED 7 5 RESISTOR CARBON 1 6W22K 5 0000140 PCS 1 R106 FILM SHAPED 7 5 RESISTOR CARBON 1 6 10 5 0000137 FILM 5 1 R107 SHAPED 7 5 RESISTOR PARGON 1 6VV1015 gt 0 0000599 FILM PCS 3 R108 F7E PCB 1 SHAPED 7 5 RESISTOR PORCELAI N 50 103 10 0200174 4 C101 C102 C103 C104 CAPACITO 2 5mm R CD11 02600
34. R C channel to form different scene modes In this circuit MIC shall not be inserted and is only available in 5 1CH mode N203A is for the purpose of reversal In addition this device is added headphone output function PHSW is low level and each channel has output when headphone is not inserted But when headphone is inserted PHSW will be high level for the mechanical settings thus LRM and SCM signals change into high level at the same time to realize muting in each channel so the signal is only outputted from headphone that is there is not signal output with each channel when connecting with headphone output 2 3 3 Bass enhancer circuit P BURST is the switch signal of bass enhancer When it is of high level and added to the base electrode of V102 V102 will be switched into conduction When the collector electrode outputs low level V107 will be cutoff when the collector electrode is of low level 100 will also be cutoff SW signal 15 normally outputted to external terminal Meanwhile the high level signal of P BURST is added to the emitter electrode of V108 V108 is positively biased and switched into conduction The collector electrode adds high level to the base electrode of V101 V101 is positively biased and switched into conduction and ground SW signal not superposing it to L R signal In reverse when P BURST is of high level V100 will be switched into conduction and SWM cannot be outputted from external terminal Meanwhile V1
35. S 1 N101 220 MC7912CT 0880325 IC GOLD SEALED PCS 1 N102 220 LM7912CT 0880381 IC GOLD SEALED PCS 1 N102 220 CD1875CZ 0882618 220 ITDA2052V 0882913 GOLD SEALED PCS 2 N105 N106 220 1940003 SOCKET 2 5mm PCS 1 XS7 1940040 SOCKET 3 96mm PCS 1 5 1940155 SOCKET 3 96mm PCS 1 XS8 4P140 2 5 FLAT 2120267 2PLUG WITH PCS XP6 CABLE NEEDLE 125 2 5 FLAT 2PLUG WITH 2121182 PCS XP13 CABLE NEEDLE IN PHASE 145 2 5 FLAT 2PLUG WITH 2121183 PCS XP9 CABLE NEEDLE IN PHASE 2300005 FUSE T6 3AL 250V PCS FL101 FL102 FUSE 3870057 0 FL101 FL102 HOLDER HEAT 15 4x10 7x45 3580085 RADIATIO PCS SRQ1 220 3580092 RADIATIO 14 8 16 AV430 PCS STICK TO 7912 N BOARD LARGE 261 128 80 250 3580215 RADIATOR 3PCS FOR POWER PCB AMPLIFIER 3870603 130 5 BRACKET BOARD HEAT RADIATOR 5 FOR POWER PIPE LARGE HEAT SELF TAP RADIATOR 1PC FOR PT 3x12H WHITE 4000516 PING CD1875 LARGE HEAT SCREW RADIATOR 2PCS ITDA2052 LARGE HEAT RADIATOR 3PCS SELF TAP BRACKET HEAT BT 3x8H WHITE 4000453 PING NOE PCS RADIATOR 1PC FOR SCREW 7812 HEAT RADIATION BOARD 3PCS FOR PCB SELF TAP BT 3x6H WHITE BRACKET POWER 4000462 PING PCS NICKEL AMPLIFIER BOARD SCREW 1PC FO
36. WEEN IN PHASE XS101 XP101 FLAT 9P75 2 5 2PLUG 2120296 PCS 1 XP25 CABLE WITH NEEDLE IN PHASE FLAT 2121187 3P 2 5mm PCS 1 X 20 CABLE FLAT 2121561 4P 2 5mm PCS 1 22 CABLE 1940002 SOCKET 2 5mm PCS 2 523 524 1940003 SOCKET 2 5mm PCS 2 X56 X512 AV1 8 4 5G 1940004 SOCKET PCS 1 XS13 BLACK 1940007 SOCKET 14 8 16 AV130 PCS 1 59 1940009 SOCKET AV100 PCS 1 5103 TERMINAL H 28 4mm 1910034 PCS 1 100 SOCKET 230 HEAT 3580092 RADIATIO 3 8 NICKEL PCS 1 STICK TO 7805 107 N BOARD GROUNDI BT 3x6H WHITE 3870591 PCS 2 NG PIECE NICKEL PLASTIC 31107 2 SIGNAL PROCESSING 3026724 PCS 2 BRACKET AV250T RU BOARD CPU BOARD 2 PCS FOR PLASTIC SELF TAP 2 1 BRACKET SIGNAL 4000197 PING PCS 4 PROCESSING BOARD AV250T RU SCREW 2PCS FOR PLASTIC BRACKET CPU BOARD SELF TAP HEAT RADIATION 4000462 PING PCS 1 BOARDIIC SCREW SEMI FINIS 5447830 PCS 1 HED PCB SEMI FINIS 5447837 PCS 1 HED PCB MATERIAL MATERIAL SPECS amp UNIT QTY LOCATION CODE NAME MODEL W1 W3 W33 W34 W36 0 6 SHAPED W42 W44 W48 W50 2100003 PCS 60 ON CORDS7 5mm W52 W59 W78 W82 W84 W85 W92 W93 6 SHAPED 2100004 PCS 13 W60 W70 W90 W2 ON CORDS10mm 2100007 CORDS 15mm SHAPED PCS W71 W77 W91 210001
37. all states and the signal flow chart is as FM AM VCD N106 CD4052 M62446 CD Input Electronic 51 input selection volume LR adjustment Channel 5 1 input C SR SL SL CD4053 channel Electronic switch 5 1 inpu SW CH 04053 SW Send to L R SEARCH Electronic N100 switch CPU follows 2 2 1 Input selection and sound field processing mode The input selection of AV250T is achieved via electronic switches CD4052 and CD4053 and the truth tables are as follows CD4052 Truth table CD4053 Truth table 5 1CH input mode Now A B 5 1CH control pins of M62446 are in high level L R channel signals of 5 1 input terminal is outputted from pin 3 13 of N101 and sent to IC N106 for volume and tone adjustment meanwhile C SR SL signals of 5 1CH input terminal are outputted from pin 14 15 4 of N102 and then respectively sent to IC N106 for independent volume adjustment And SW signal of 5 1CH is outputted via pin 4 of N103 and then sent to M62446 after being amplified by N107A Three analog input modes 250 totally has three analog input modes digital tuning demodulation signal VCD and DVD which are controlled via A B signal respectively AV250T totally has three sound field modes Standard Cyber Logic and Hi Fi 1 Standard Under the control of overall CPU when bass enhancer is off L R channel and subwoofer output are available when bass enhancer is on only L R channel output is available 2 Hi Fi Under the
38. ch signal inputs to enter normal play 2 When pressing SEARCH button on the remote controller it is converted from optical signal to electric signal by the remote control receiver of panel Pin 14 of CPU emits a high level to conduct V102 and search according to the same previous process 2 4 3 Spectrum Analysis Circuit see the following figure Spectrum analysis circuit is divided into three parts N105C DISPLAY 04 3 CD4051 Auto Frequency spectru point m and gating gain adjustme 7 segmeht band pass CPU BV 103 V104 Pin 28 of CPU conversion Automatic spectrum gain adjustment circuit To avoid two situations that spectrum display amplitude is too low when input signal is too weak spectrum display is in full screen when input signal is too strong AV250T sets automatic spectrum gain adjustment circuit using single track one from eight electronic analog switch its true value diagram is as follows CD4051Truth table eee Its main working principle is to change the value of inverse ground resistance of transmittal N104 to change the transmittal gain multiple Lets see the detailed work of the whole circuit We ve referred that spectrum analysis signal source DISPLAY is sent to the co phase input end of transmittal N105C to amplify Its amplification factor is determined by the value of the resistance connecting with the electronic switch of its invers
39. d the circuit structure is the same with the above The function of temperature compensation tube V106 in circuit has two it is the base bias of geminate transistors firstly and its working state determines the static working current of composite power amplifying stage that is through adjusting the gating degree of V106 we may set the static working point of composite power amplifying stage The usual means is to change the base electrode resistor of V107 it may also automatically adjust the working state of composite power amplifying stage after the temperature increases with the adjustment process shown as follows Total current of output stage working current leakage current When temperature increases the increase of leakage current leads to drift of static working point and meanwhile leakage current of V106 increases The decrease of Uce makes the bias current of output stage decrease the working state change and the working current of back stage decrease to achieve the function of temperature compensation Introduce voltage negative feedback into power amplifier circuit of AV250T composed of R121 R109 C105 which is capable of stabilizing static working point of differential stage AV250T adopts direct output means and R111 C116 connected to output terminal compose Joubert Network capable of avoiding high frequency self excitation caused by the AC inductive reactance of speakers voice coil Mote control when pressing MUTE butto
40. e end N104 When the main volume is large CPU will automatically increase the value of ground resistance and decrease the amplification factor when the main volume is small CPU will automatically decrease the value of ground resistance and increase the amplification factor Amplitude sampling circuit signal amplified by N105C is sent via C115 coupling to seven band pass filters composed of transmittals By setting its capacity of feedback capacitance its frequency band range can be determined The frequency value of superscript of the output points is the central frequency point of the frequency band The output end of each band pass filter is connected with a half wave rectifier circuit The amplified A C signal is rectified to direct current The circuit is mainly to achieve frequency point sample It can display the amplitude of all frequency points of the whole sound signal via direct current voltage If the low frequency of sound signal is stronger the current voltage of output end of 35HZ and 100HZ band pass filter is higher When high frequency is stronger the current voltage of 10K and 16K band pass filter is higher The output ends of the seven band pass filter are connected with the seven input ends of electronic switch N108 CD4051 These electronic switches will quickly circularly switch among frequency points referring to previous true value diagram Pin 3 output end of N108 will output a string voltage value representing frequency
41. ignal During delay adjustment for PT2399 first control signal is given to CPU which controls N207 after being expanded N211 IC CD4094 and connects with pin 6 of PT2399 by selecting different resistance values for purpose of delay adjustment Echo control 15 to change the resistance value at the connection point to 229 so as to change the superposition on through connect signal for echo control The wide sound field processing control signal of SOK s karaoke is in wide sound field mode when it is high level and now the signal of OK R is the OK signal inverted by N204A A sense signal of OK SW on the MIC plug detection together with the network made up of V200 When MIC is not plugged it is low level when plugged it is of high level Karaoke auto mute function is also available When P KT fails to detect signal for a continuous period CPU will send a P KM signal to mute karaoke and avoid MIC receiving noise which may affect on sound effect Signal flow chart of scene mode AV250T has a special function that switching between 5 scene modes is available without karaoke which is fulfilled through part of karaoke When pin 9 10 of N205 are of high level sampled L R C signals are outputted via pin 3 through N205 gating After amplification by N203 one way is connected directly and another way is sent to internal of PT2399 for echo delay adjustment controlled by IC CD4049 with the adjusted effect superposed to L
42. n Eight Video board Video board fulfilis the functions of input output and switch of the video with the schematic diagram shown as the following figure 101 0 051 This switch function is realized through an electronic switch IC CD4051 When high and low level of control signal A and are changing IC CD4051 switches between VCD and DVD and video signal is outputted by pin 3 VOUT Chapter Three Servicing Process 1 No output for Karaoke Firstly confirm whether microphone is good Whether the pre amplification circuit and checking circuit of microphone work normally Whether the microphone volume adjustment works normally Whether high low frequency boost circuit works normally Whether mute circuit of microphone works normally Note For MIC size is disordered on the market that MIC is too long or too short will both lead to no output of microphone Note here please check whether the microphone checking signal P KT is able to overturn when signal output is available Note check whether the periphery circuit of volume boost IC2315 or IC M62429 is normal and whether the voltage and data line has abnormalities Note check whether the triode in the microphone circuit has damage and whether the mute control signal line P KM is normal 2 Power supply not connected Check whether the power cord socket has been well connected Whether fuse FL1
43. n on remote controller a mute signal achieved through signal photoelectric conversion performed by remote control receiver is sent to CPU and then a high level mute order is outputted from pin 35 36 of CPU to make V115 V101 and V116 on left right channel signal has short circuit to ground to fulfill mute control function C SR SL power amplifying circuit compared with the former models the three channels of AV250T adopt special power amplifiers LM1876 and IC LM1875 As for LM1876 it has 15 pins in all in which pin 2 15 4 are its positive negative power pin and pin 7 8 12 13 are its in phase or reverse input terminal The rated output power of each channel of this power IC may be up to 20W with auto mute function when power on as for 1875 it has 5 pins in all It is good performance power amplifying IC with very simple application circuit and 15W power output in rated state Pin 5 and 3 are positive and negative power supply pin Section Seven Power board Power board supplies working voltage required by each unit circuit and over current over voltage protection unit Protection unit circuit is emphasized here The protection means of L R and channel is fulfilled through disconnecting relay Y100 when starting up so as to disconnect the output SR and SL channel achieves protection function through mute AV250T is with power on protection central point over voltage over current protection and standby protection
44. nect AR V103 is connected te channel voltage 4 and protection on each channel is R116 decrease start up When below __ 102 3 5V Over current and short circuit protection An over current sampling triode is connected to the output load resistor of L R channel Sampling tube of L channel is V114 and load resistance is R126 and R127 The other three channels power amplifying IC is with over current protection inside Only L channel appears over current the pressure drop produced on R126 and R127 will increase quickly Once the pressure drop on R129 is above 0 7V V114 will be on and V103 is also on Finally relay disconnects and protection circuit starts up Pressure drop Over current on R126 Relay sampling L R127 V114 pole disconnects triode is l channel gt gt gt gt VI03 increases is on voltage and protection connected to is V114 when over decrease starts up each channel current The same when R channel has over current voltage on R159 will be above 0 7V to make V129 on and then V103 on Finally relay disconnects to reach the purpose of protecting speaker 4 Standby protection When standby time is up to 10 minutes and standby by force is needed PRC signal outputted from pin 34 of CPU is high level which makes V100 saturated and on through VD108 R101 to make V103 on Finally relay disconnects to reach the result of standby and energy saving Sectio
45. point signal amplitude see next diagram Note the voltage amplitude in diagram is uncertain Interval of switch x Frequency point cycle gating period Discharge of high level 100HZ 35H Interval of switch Time for charge Time for charge AID conversion and output circuit display two situations 1 When no signal input pin 28 of CPU sends a high level to B pole of V104 The positive end of N102B is low voltage the inverse end of N102B gets partial voltage of R189 and R172 making N102B output a low level that is triode V105 stops and C pole of V 105 will give a high level to pin 12 of CPU to let CPU not conduct AD conversion pin 6 7 8 of CPU are inactive and keep high level 2 When the machine has detected the signal the inverse end of N102B has a current voltage representing 35HZ signal amplitude pin 28 of CPU is converted into low level and 5V voltage charges for C137 via V103 When reaching the voltage value of inverse end the comparator converts and N102B outputs high level Once CPU receives low level signal it stops 35HZ level gating and converts into next frequency point 100HZ During conversion pin 28 of CPU outputs an instant high level to conduct V104 leak the voltage capacity of 137 and make the of N102B restart to charge 100HZ from 0 When the charge of 100HZ finishes the charge and discharge of next frequency point begin and such p
46. rocess occurs circularly under the control of CPU The charge time form O level to the occurrence of output conversion represents the signal amplitude of current frequency point the larger the amplitude the longer the time and the amplitude displaying in screen is higher the smaller the amplitude the shorter the time and the amplitude displaying in screen is lower Digital pulse outputted from N102B output end is added by V105 s inverse to pin 12 of CPU which handle it and output to panel to display dynamic frequency in screen The display of original frequency points is sequential However the above circular process is extremely quick thus what we see in screen is the progress of the whole spectrum displaying synchronously Section Five Panel control and display circuit The panel control and display circuit of AV110 adopts the special IC 101 PT6311 whose external buttons of pin 10 11 12 13 scan buttons matrix After receiving the control command of users to the machine processing is done inside and then outputted by two ways one way is sent to display screen to display the working status and the other way is transmitted to CPU through pin 5 6 8 9 to ask for performing and finishing the corresponding control function N102 is remote control receiver which transforms the received infrared remote control signal into electronic signal and then send it to pin 13 of CPU so as to complete remote control function Section Six Power amplifier
47. s English intelligent operation interface 12 Bass enhancer function 13 Digital tuning function 14 Video switch function 15 Headphone output function 16 Full remote control operation Chapter Two Operating Principle Section One Overall structure The whole unit of AV250T is mainly composed of the following parts 2 1 1 Volume board input selection Cyber Logic and bass enhancer control 2 1 2 Signal processing board Karaoke signal processing and front stage amplifying of 5 1Ch signal 2 1 3 CPU board whole machine control unit breadth sampling circuit and auto searching circuit 2 1 4 Control panel VFD display remote control and keyboard scanning and fulfill man machine conversation function 2 1 5 Power amplifier board perform power amplifying for 5 1CH signal or other analog signals 2 1 6 Power board supply the working voltage required by each unit circuit and over current over voltage protection unit 2 1 7 Digital tuner receive radio signal and then send to power amplifier to perform signal amplifying processing 2 1 8 Video input and output board fulfill video input output and video switch function Section Two Volume board AV250T has 4 kinds of input modes in all FM AM VCD DVD and 5 1CH sampling from L R channel of AV250T after Cyber Logic function SL and SW channel signals are achieved In this circuit electronic analog switch is adopted to fulfill the switch in
48. the filament voltage is close to be low Whether CPU power supply is normal Yes Whether signals from control panel drive IC to display screen No pin are normal Yes May probably cause Can that judge the badness of control display screen is panel drive IC not good Yes that the Can judge problem occurs in CPU board 4 No output Check whether the analog Note check whether IC power electronic switch IC can be cord is normal and signal gated in this path when there cords P INA and P INB which is signal input control IC gating are normal Yes Yes Check whether tone adjustment Check whether power on 1 62446 75347 front stage has signal input checking circuit works normally Yes Check periphery circuit of IC is Check whether tone adjustment No 1 62446 or 75347 front stage has signal input normal IC power supply and whether CPU control signals P VDA P VCK and P VST are normal Yes Whether power amplifier board has signal input Whether power Check whether power Whether main channel mute control amplifier board tube has abnormalities line P LRM and center surround has signal input of punch hole mute control line P CSM are normal Schematic amp PCB wiring diagram CPU board schematic amp PCB wiring diagram
49. wer amplifier The clock and data line of tuner are shared with LM62446 and the other two control lines are connected to CPU directly L R signal processed by the tuner can be sent to N101 IC CD4052 directly to input the selected channel Section Three Signal processing board The signal processing board superposes mixes and amplifies 5 1CH signal sent from the volume board voice signal from the voice board and Karaoke signal 2 3 1 Karaoke circuit of AV250T This circuit processes human voice through power amplifier and reproduces it via speaker It includes human voice beautification circuit wide sound field processing circuit Karaoke echo and delay adjusting circuit IC and its functions for Karaoke S N of IC Name of IC Functions of IC N201 PT2308 Transmittal pre amplification for Karaoke signal N200 PT2315 Karaoke volume control including tone control N205 CD4053 Electronic switch N209 PT2399 Karaoke echo processing N207 CD4051 Karaoke delay adjustment N208 CD4051 Karaoke echo adjustment 204 4558 Phase inverter PT2315 functional pin S N Name of pin Description 1 REF Reference voltage 1 2VDD 2 VDD Power supply 3 AGND Analog 2 Treble control pin of L R channel 6 RIN R channel input 7 LOUD R Loudness control pin of R channel 9 LOUD L Loudness control pin of LR channel 11 LIN L channel input
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