NAD C 720BEE Service Manual
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NAD C 720BEE Service Manual

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NAD
C 720BEE
STEREO
RECEIVER

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Summary of Contents for NAD C 720BEE

  • Page 1 C 720BEE STEREO RECEIVER...

  • Page 2: Table Of Contents

    TABLE OF CONTENTS DESCRIPTION P A G E SERVICE CAUTION……………………………………………………………..3 REAR PANEL/FRONT PANEL VIEW………………………………………...4 SPECIFICATIONS………………………………………………………….5-7 ALIGNMENT PROCEDURE……………………………………………..6-7 WIRING DIAGRAM………………………………………………………………8 BLOCK DIAGRAM……………………………………………………. …….9-15 ALIGNMENT PROCEDURE……………………………………………..16 SCHEMATICS……………………………………………………………….17-20 PCB LAYOUT……………………………………………………………… 21-24 SPECIAL FUNCTION/TROUBLE SHOOTING GUIDE…………………..25 ELECTRICAL PARTS LIST…………………………………………….26-34 EXPLODED VIEW……………………………………………………………..35 EXPLODED VIEW PARTS LIST……………………………………………...36 PROTECT IC CHANGE ....……………………………………..……...37 - 2 -...

  • Page 3: Service Caution

    SERVICING PRECAUTIONS CAUTION Before servicing the Stereo Receiver covered by Electrostatically Sensitive (ES) Devices this service data and its supplements and addends, read and Some semiconductor (solid state) devices can be damaged follow the SAFETY PRECAUTIONS. NOTE: if unforeseen easily by static electricity. Such components commonly are called Electrostatically Sensitive (ES) Devices.

  • Page 4: Rear Panel/Front Panel View

    FRONT PANEL/REAR PANEL 1&2 FM&AM ANTENNA 11. RECORD OUT/ZONE 2 3. SPEAKER A&B 12. TAPE IN 4. SWITCHED AC OUTLET 13. AUX INPUT 5. AC LINE CORD 14. VIDEO INPUT 6. VACATION SWITCH ON/OFF 15. CD INPUT 7. SOFT CLIPPING 16.

  • Page 5: Specifications

    SPECIFICATIONS NAD C720BEE Stereo Receiver Note: Specifications are measured in accordance with EIA Standard RS-490 (IHF A-202) for amplifiers and ANSI-IEEE Standard 185(1975), i.e. input and converted to equivalent 300-ohm values. Power Amplifier Section CONTINUOUS AVERAGE POWER 50W (17dBw) OUTPUT AT 8 OHMS...

  • Page 6: Alignment Procedure

    Signal-to-Noise ratio 110dB ref 500mV (A-weighted, 1kHz CD In, Pre-Out) Rated distortion (THD)(20Hz –21kHz) 0.03% Channel Separation 70dB 2V CD IN, 2V Pre-Out,1k shorted,1kHz Input Sensitivity 320mV for 1V out Input Overload Frequency response tone defeat +/-0.1dB tone on +/-0.5dB THD (SUB OUT) 0.03% (2V CD in, 2V SUB out;...

  • Page 7: Specifications

    Capture ratio (at 45 and 65 dBf) 3 dB AM rejection (at 65 and 85dBf) 40 dB Alternative channels Selectivity 40 dB (RF±400KHz, at 30dB) Image rejection(at usable sensitivity) 70 dB I.F. rejection (at usable sensitivity) 70 dB Pilot suppression (1kHz, 60dBu) 55 dB Mono, 1kHz, 60dBu 0.8%...

  • Page 8: Wiring Diagram

    WIRING DIAGRAM AC POWER PLUG PCB-6 AC OUTPUT BOARD POWER SWITCH CB59 PCB-1 MAIN BOARD WB01HS-001(C) UL1672 AWG#18 UL1672 AWG#18 FPC 1.25-17P-180mm WB05HS-001(AH) RED, 130mm RED, 100mm CB34 WHITE CB57 CB58 (Insert) CB34 CB55 CB45 CZ36 CZ37 CB56 PCB-9 MUTE BOARD UL2468 AWG#26, WHITE, 150mm CB47 CB53...

  • Page 9: Block Diagram

    BLOCK DIAGRAM JK41 (4,5,6,7,13,14) - 9 -...
  • Page 10 DATA DATA DATA...
  • Page 11 ICS BLOCK DIAGRAM uPC1237HA MAIN BOARD: IC44 VCC ON Overload Detector MUTE Output Offset Detector AC---OFF detector Switch for latch/automatic --reset AT24C64A KEY BOARD: IC705 PIN CONFIGURATION FUNCTION PIN NAME A0--A2 ADDRESS INPUTS SERIAL DATA SERIAL CLOCK INPUT WRITE PROTECT START STOP LOGIC...
  • Page 12 AT89C55WD KEY BOARD : IC704 PIN CONFIGURATION P2.0 ------ P2.7 P1.0 ------ P1.7 PORT 0 DRIVERS PORT 2 DRIVERS PORT 0 RAM ADDR. PORT 2 QUICK REGISTER LATCH LATCH FLASH PROGRAM STACK ADDRESS REGISTER PIONTER REGISTER TMP2 TMP1 BUFFER INCREMENTER INTERRUPT,SERIAL PORT AND TIMER BLOCKS PROGRAM...
  • Page 13 CD4094 MAIN BOARD:IC32&IC33 KEY BOARD: IC707 PIN CONFIGURATION STROBE DATA OUTPUT ENABLE SERIAL CLOCK SERIAL STAGES 3 - 7 STROBE LATCH LATCH LATCH * VDD OUTPUT ENABLE 3 - STSTE STATE STATE * ALLINPUTS PROTECTED BY CMOS PROTECTION NETWORK TL082CP/D MAIN BOARD: IC3, IC4, IC34, IC43 OUTPUT A INVERTING INPUT A...
  • Page 14 NJU7313AL MAIN BOARD: IC31 PIN CONFIGURATION R-COM1 L-COM1 R-COM2 L-COM2 R-COM3 L-COM3 DATA L-COM 1 R-COM 1 L-COM 2 R-COM 2 R-COM 3 L-COM 3 DATA Control Circuit - 14 -...
  • Page 15 uPD16311 MAIN BOARD :IC703 Command decoder Dimming circuit Seg1 Dout Display memory Serial I/F 20bit x 16 word Seg12 Timing generator key scan key scan memory (4x20) Seg13/grid16 Grid 1 Key1 Key4 Grid 8 Seg20/grid9 5-bit latch LED 1 LED 5 (+5V) (0V) (-30V)

  • Page 16: Alignment Procedure

    ALIGNMENT PROCEDURES I. INITIAL A. LOWEST VOLUME ADJUSTMENT 1. Tune the volume pot to lowest state. 2. Input a high voltage signal such as 5V from CD input. 3. Connect a oscilloscope to L channel binding posts. 4. Observing the oscilloscope,adjust VR301,make the output of speakers become to the lowest level.

  • Page 17: Schematics

    MOTO POT FOR Vm1.6 PREAMP AMP CIRCUIT FOR Vm1.7 PCB-1: MAIN BOARD FOR Vm5.0 PCB-5: POT BOARD FOR Vm5.0 RT33A RT33B RT33C C720BEE TONE CONTROL CIRCUIT C325 POTALPS CZ34 CB31 POTALPS POTALPS 47u/25 TO VOLUME POT C720BEE INPUT SELECT CIRCUIT C321 0.1u R325...
  • Page 18 SCHEMATIC DIAGRAM (1/4) C720BEE POWER AMP CIR. R D412 +37V +18V +46V L OUT R154 R101 R130 C436 1N4148 39k,MF,5% 82/1W FS R126 R142 Q103 C114 I/V For C2240 R119 0.1u 10% R12/1 C12/1 10u/35V 2K7/2W FP 22,MF,5% Over C103 82,MF,5% R128 47uF/25V...
  • Page 20 PROTECTION Flash OP SEL CLK OP SEL DATA speak a OP SEL ST IP SEL ST2 speak b IP SEL CLK IP SEL DATA IP SEL ST ENCODE 1 ENCODE 2 VIDEO Standby IP SEL DATA IP SEL CLK IP SEL ST2 IP SEL ST Flash DISC...

  • Page 21: Pcb Layout

    C444 C434 Q413 R312 Q414 C312 R381 R457 J108 J107 R477 D417 J106 D418 R474 R12/2 R486 R12/1 R469 R472 R468 R473 J139 J168 J167 J166 C330 R324 J218 R320 R492 J297 R211 R111 J265 J231 R104 R102 R202 R201 R101 R105 R204...
  • Page 22 PCB-2: POWER BOARD FOR Vm5.0 CB55 CB58 CB57 C524 J516 C535 CB56 C523 COPYRIGHT C 2004 NAD ELECTRONICS VFD 2 NAD C720BEE POWER BOARD Vm5.0 J515 VFD 1 TRIG ACDET C517 C518 +37V -37V -30V CB53 CB54 R531 D531 D51...
  • Page 23 R717 R718 D707 R750 J752 J730 J705 CZ702 (+12V) J731 J706 R749 J707 (+5V) J708 (-30V) R720 R721 R618 J709 J746 J710 J711 J753 C611 J718 J714 D703 J719 J715 J732 (GND) J712 J720 D705 J721 J713 (GND) J733 J722 (GND) D702 J734...
  • Page 24 PCB-3: KEY BOARD (BOTTOM VIEW) R741 C703 R701 R702 R703 R704 IC703 PCB-3: KEY BOARD (TOP VIEW) NAD C720BEE VFD BOARD Vm5.0 IC701 CZ703 COPYRIGHT C 2004 NAD ELECTRONIC PCB-10:HEADPHONE BOARD PCB-9: MUTE BOARD PCB-9: MUTE BOARD (BOTTOM VIEW) (TOP VIEW)

  • Page 25: Special Function/Trouble Shooting Guide

    SPECIAL FUNCTION Simultaneously press ''FM''+"CD": C-version (230V) factory reset Simultaneously press ''FM''+"DISC": AH-version (120V) factory reset TUNER SECTION Simultaneously press ''FM''+"AM": displays software version Press "AM"+"TAPE": all icons in the VFD DISPLAY light up In addition, in tuner mode, press the "MEMORY" key once, and then press the "DISPLAY" key once.This will allow you to change the current display;...

  • Page 26: Electrical Parts List

    ELECTRIAL PARTS LIST CIRCUIT NO. PART NO. DESCRIPTION PCB-1: MAIN BOARD IC3, IC4, IC34, IC43 03-00082-00 TL082CP/D IC44 03-01237-00 UPC1237HA IC32, IC33 03-04094-00 CD4094/HEF4094 IC31 03-07313-00 NJU7313AL DIODES D13, D14, D15, D16, D17, D23, D24, D25, D26, D27, D37, D38, D39, D310, 33-44148-02 1N4148 D311, D312, D315, D42,...
  • Page 27 ELECTRIAL PARTS LIST CIRCUIT NO. PART NO. DESCRIPTION C120, C220, C434 24-22312-04 22n/100V 10% C119, C219, C327, C328 25-22361-05 22n/63V 5% C118, C218 25-10461-04 0.1u/63V 5% C17, C114, C115, C117, C27, C214, C215, C217, C319, C320, C321, C322, 25-10412-02 0.1u/100V 10% C337, C338, C345, C346, C411, C412, C329, C330, C347...
  • Page 28 ELECTRIAL PARTS LIST CIRCUIT NO. PART NO. DESCRIPTION R429 07-10512-10 5.1K ±5% 1/4w R381 07-10512-00 5.1K ±5% 1/6w R480 07-10622-10 6.2K ±5% 1/4w R12/1 07-10682-10 6.8K ±5% 1/4w R402, R469, R470, R471, 07-10103-10 ±5% 1/4w R404 R364, R365, R366, R449, 07-10103-00 ±5% 1/6w R450, R493, R494, RI5...
  • Page 29 ELECTRIAL PARTS LIST CIRCUIT NO. PART NO. DESCRIPTION INDUCTORS L11, L21 08-01010-00 POTS RT31, RT32 09-01103-07 10KA RT34 09-01203-06 20K MN VR12, VR22 09-02301-00 VR301, VR302 09-02101-00 SWITCHS SW31 11-02202-00 TONE DEFEAT SW41 11-05202-12 SOFT CLIPPING RELAYS RL31, RL32, RL33, RL34 12-02101-02 JRC-27F/012/S RL35, RL36...
  • Page 30 ELECTRIAL PARTS LIST CIRCUIT NO. PART NO. DESCRIPTION J10, J11, J12, J13, J14, J21, J34, J38, J39, J40, J41, J43, J45, J46, J47, J48, J49, J50, J52, J55, J58, J59, J60, J85, J86, J87, J93, J94, J120, J123, J124, J125, J126, J127, J128, J129, J130, J131, 21-06750-00 L=7.5mm...
  • Page 31 ELECTRIAL PARTS LIST CIRCUIT NO. PART NO. DESCRIPTION CAPACITORS C63, C64 05-22012-01 22p/100V ±10% C611 05-15012-00 15p/100V ±10%(OUT MODULE) C611 05-40012-00 40p/100V ±10%(IN MODULE) C610, C69 05-10112-00 100p/100V± 10% C61, C62 05-22112-00 220p/100V ±10% C65, C66, C67, C68 24-10461-00 0.1u/63V± 20% RESISTORS R617, R618, R619, R620 07-10100-00...
  • Page 32 ELECTRIAL PARTS LIST CIRCUIT NO. PART NO. DESCRIPTION 06-10051-00 10u/50V 20% RESISTORS R561, R565 07-10101-10 ±5% 1/4w R532 07-10221-10 ±5% 1/4w R558, R559, R560, R562 07-10102-10 ±5% 1/4w R534 07-10222-10 2.2K ±5% 1/4w R566 07-10472-10 4.7K ±5% 1/4w R544, R563, R564 07-10223-10 ±5% 1/4w R533...
  • Page 33 ELECTRIAL PARTS LIST CIRCUIT NO. PART NO. DESCRIPTION C704, C705, C706, C707, 24-10461-00 0.1u/63V± 20% C708, C718, C719, C723 C720 06-10051-00 10u/50V 20% C717 06-10111-00 100u/16V 20% RESISTORS R718 07-10301-10 ±5% 1/4w R717 07-10331-10 ±5% 1/4w R742 07-10471-10 ±5% 1/4w R710, R713 07-10821-10 ±5% 1/4w...
  • Page 34 ELECTRIAL PARTS LIST CIRCUIT NO. PART NO. DESCRIPTION CIRCUIT NO. PART NO. DESCRIPTION RT33 09-01203-05 20KB CONNECTER CB31 13-22509-00 9PIN; 2.5mm PCB-9: HEADPHONE BOARD CIRCUIT NO. PART NO. DESCRIPTION RESISTORS R458, R459 07-30101-04 2W ±5% CONNECTER JK41 17-02001-00 PH-2ASW SCN 2.5A-3D;XHB 2.5A-3Y; CZ45——CB45 14-72003-10 26AWG UL2468# ;...

  • Page 35: Exploded View

    EXPLODED VIEW T001 S006 S016 S014 S015 C009 S011 C008 R005 C007 R006 C004 R004 R003 C003 C006 S001 S002 S009 S001 S016 C017 C015 R001 C005 C012 S012 C016 S014 S006 S006 S015 R002 C010 S010 S002 S008 S013 S002 S007 S006...

  • Page 36: Exploded View Parts List

    EXPLODED VIEW PARTS LIST REF.NO PART NO. DESCRIPTION Qty. REF.NO PART NO. DESCRIPTION Qty. 66-047001-1 75-005001-0 Sleeve C001 Chassis F024 66-047003-0 Service Cover 66-011006-0 IR Bracket C002 F025 66-001009-0 Clamper 36-01012-00 C003 F026 70-047001-1 Main Heat Sink 75-047004-0 VFD Bracket C004 F027 66-001010-0...

  • Page 37: Protect Ic Change

    PROTECT IC CHANGE 100k 4.7V 100N 220k 2SA1015GR 2SA1015GR 220k 820k 180k 100k 2SA1015GR 2SC1815GR 2SC1815GR 2SC1815GR 1N4148 1N4148 2SC1815GR 2SC1815GR 0.22UF 2SC1815GR 4.7k 2SC1815 100k 100k Protect Module CON8 This Protect Module replaces Protection IC 44 Remove the part below: R442 Remove 56K Ohm resistor.
  • Page 38 © NAD 2005 NAD ELECTRONICS LTD TORONTO...

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