Audiolab-8000S-int-sm维修电路原理图.pdf

? ? RadioFans.CN 收音机爱 好者资料库 introduction No part of this document may be reproduced or transmitted in any form or by any means, electronic or mechanical, for any purpose, without the express written permission of International Audio Group Limited (IAG). This manual is for the exclusive use of IAG, its approved distributors and approved UK service agents. No part of this manual shall be transferred to a third party without the written permission of IAG. It is the responsibility of the user to ensure that all the information contained in this manual is current. Notification for new issues of this manual and minor updates will be given via the IAG web-site or on request. This manual has been prepared with the greatest care, it is intended for information only and no liability shall be accepted for errors or changes to specification. For further service information, parts lists and updates, please contact our web-site. 2005 International Audio Group Limited. All rights reserved. Notification for new issues of this service manual will be given via the Audiolab web site:- issue number :- 2005/001/8000SG GR RP P0 00 00 00 03 3. .0011 issue date :- September 04 20052 2 5 5 . . 0 0 1 1 . . 1 1 9 9 92 2 5 5 . . 0 0 1 1 . . 1 1 9 9 9 99999 RadioFans.CN 收音机爱 好者资料库 index 1.0safety and servicing notes 1.1Safety precautions.1 1.2Electrostatic discharge precautions .1 1.3Soldering.1 2.0front and rear panel layouts 2.1Front panel controls .3 2.2Rear panel connections.3 3.0disassembly instructionsdisassembly instructionsPages 4 and 5 DELETED 4.0functional tests 4.1Test equipment required .6 4.2Functional test procedure.7 5.0performance tests 5.1Test equipment required .11 5.2Performance test procedure .12 6.0test points 6.1Functional and performance test points .16 7.0circuit schematics 7.1Master schematic diagram (SCH267M-01-05).17 7.2Line amplifier left channel schematic (SCH26701-07-02) .18 7.3 Line amplifier right channel schematic (SCH26701-08-02).19 7.4Power amplifier left channel schematic (SCH26701-09-02).20 7.5Power amplifier right channel schematic (SCH26701-10-02).21 7.6Power supplies schematic (SCH26701-01-02) .22 7.7Protect and turn on schematic (SCH26701-06-02) .23 7.8Digital system controller schematic (SCH26701-02-01).24 7.9Digital system interface schematic (SCH26701-03-01).25 7.10Input interface schematic (SCH26701-04-04) .26 7.11Relay coils schematic (SCH26701-05-01) .27 7.12Front panel schematic (SCH26702-01-01) .28 7.13Speaker outputs schematic (SCH26703-01-01).29 8.0printed circuit board layout 8.1Printed circuit board layout (top view).30 8.2 Printed circuit board layout (bottom view).31 9.0technical data 9.1 8000S Technical specifications.32 9.2International standards.34 1 1.0 safety and servicing notes 1.1Safety precautions 1.This unit is Class II, which means that it is not connected to the protective earth system. All live voltages are insulated from the case by double insulation. 2.Do not attempt to service unless qualified to do so. 3.Disconnect unit from AC power supply before removing cover. 4.Components marked with the symbol on the circuit schematic are safety critical and must only be replaced with an identical component, or an alternative approved by the manufacturer. 5.Switch unit off, and disconnect from supply before making and breaking any connections. 6.Do not adjust any controls unless instructed to do so in this manual. 1.2Electrostatic discharge precautions Electrostatic discharge (ESD) is due to charges produced by insulating materials rubbing together. Humans collect electrostatic charge through normal activities when clothes rub together and when walking on carpet. This charge may be discharged suddenly when you touch a conductor. If the conductor is connected to a sensitive electronic circuit, you may damage the components. It is also possible to reduce the life of components without causing any obvious damage. To prevent ESD damage, it is necessary to follow these guidelines. 1.Prepare work area. Place an ESD protective mat on the bench, strapped to the protective earth circuit. 2.Prepare yourself. Put on an ESD protective wrist band, strapped to the protective earth circuit, or to the ESD protective mat. 3.Keep all PCBs removed from unit in ESD protective bags. 4.Keep all replacement electronic components, PCBs and stock items in ESD protective bags or boxes. 5.Be particularly careful with components marked with the following symbol: 1.3Soldering How to de-solder components Components should be removed, wherever possible, using a de-soldering tool. Be careful not to damage tracks and pads by applying too much pressure. How to make good solder joints 1.Ensure surfaces are clean. 2.Keep soldering iron clean and wetted with solder. Use an appropriate bit. Do not leave soldering iron on when not in use. 2 1.0 safety and servicing notes 3.Apply soldering iron to both component lead and pad before applying solder. Make sure that the soldering iron is applied long enough for the solder to wet properly, but do not apply for too long or component damage may occur. 4.Allow a small gap between component body and pad. Solder must not reach the base of the component. How to detect acceptable joints 1.Solder joints should have from a shiny to satin lustre and a generally smooth appearance. 2.Solder should have wetted both the component lead and pad. 3.There should be a concave meniscus between the objects being soldered. The angle of solder to pad should be less than 90 unless the solder joint extends over the edge of the pad. 4.Solder should fill the component pad and wet component lead around the full circumference (360). How to detect unacceptable joints 1.Poor wetting produces a bead of solder. The fillet will be convex instead of concave, and there will not be a feather edge. 2.On double-sided PCBs, solder should wet all round plated-through hole, on both sides of the PCB. Cleaning up after soldering 1.Flux is very corrosive. Remove with IPA (propan-2-ol) before completing the job. 2.Remove any solder balls and splashes from the unit. 3.Check all new solder joints and ensure all PCBs are clean before replacing covers. 4.After replacing covers, clean the case and any display windows with a damp cloth. Do not use any organic solvents. If scratched, replace display windows. Trim Line ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? 6 4.0 functional tests These notes are provided to assist you in servicing the amplifier. The circuit schematics are marked with typical voltage levels, which may assist in defining the cause of any problem. 4.1Test equipment required Equipment Digital Multimeter Dual Tracking DC Power Supply Various Leads Specification Accuracy better than 0.5% in V and mV ranges Output: 32 V DC 2 A Positive terminal of negative supply must be connected to negative terminal of the positive supply unless internally linked VmAVmA -ve+ve-ve+ve Select Tracking 0 V+32 V-32 V Black= -ve Red= +ve Green = 0 V Figure 4.1 - Functional test set-up 7 4.0 functional tests 4.2Functional test procedure For test point (TP) references, see section 6.0 Test Points. No 4.2.1. 4.2.2. 4.2.3. 4.2.4. 4.2.5. 4.2.6. 4.2.7. 4.2.8. 4.2.9. Action Disconnect all cables from amplifier Check voltage setting Check fuse type Check fuse resistance Set up power supply Remove cover Connect supplies as shown in Figure 4.1 Apply DC voltage to amplifier Measure left channel supply rails Test Equipment Multimeter set to Dual tracking DC power supply Dual tracking DC power supply Dual tracking DC power supply Multimeter set to V DC Details Read ratings label on rear of amplifier. Open fuse holder in power socket on rear panel. Rated supplyFuse Type 230 V AC T2.5A L250V 115 V AC T4A 125V 110 V ACT4A 125V Fuse and spare fuse should be low resistance. Set output voltage to 32 V, current limited to 500 mA. With supplies off, connect positive output of supply to positive terminal of reservoir capacitor negative output of supply to negative terminal of capacitor No connection is required to 0 V terminal of power supply. CAUTION: Do not connect with wrong polarity. Check supply outputs are 32 V and switch output on. Current output should be <300 mA negative supply and <600 mA positive supply. If higher, turn RV701 (TP 24) and RV801 (TP 25) fully anti-clockwise. Continue with test procedure of current output is 180 mA 25 mA negative supply and 515 mA 25 mA positive supply. If higher, switch off and investigate. Measure voltage across D713 (TP 1+ and TP 1-) and D714 (TP 2+ and TP 2-). Voltage should be 32 V 0.25 V. 8 4.0 functional tests No 4.2.10. 4.2.11. 4.2.12. 4.2.13. 4.2.14. 4.2.15. 4.2.16. 4.2.17. Action Measure right channel supply rails Check preamplifier supply rails Left channel Check power amplifier Left channel Measure amplifier offset Left channel Measure preamplifier Right channel Check power amplifier Right channel Measure amplifier offset Right channel Measure preamplifier Test Equipment Multimeter set to V DC Multimeter set to V DC Multimeter set to V DC Multimeter set to mV DC Multimeter set to V DC Multimeter set to V DC Multimeter set to mV DC Multimeter set to V DC Details Measure voltage across D813 (TP 3+ and TP 3-) and D814 (TP 4+ and TP 4-). Volatge should be 32 V 0.25 V. Connect negative probe to 0 V (TP 0). Connect positive probe to 30 V test point (TP 19). Voltage should be 28 V 3 V. Connect positive probe to 10 V test point (TP 15). Voltage should be 10 V 0.3 V. Connect positive probe to 5 V test point (TP 16). Voltage should be 5 V 0.3 V. Measure voltage across R731 (TP 5+ and TP 5-). Voltage should be 0.85 V 0.1 V. Measure voltage across R735 (TP 6+ and TP 6-). Voltage should be 0.85 V 0.1 V. Connect negative probe to 0 V (TP 0). Connect positive probe to R749 (TP 9). Voltage should be <5 mV. Connect positive probe to R518 (TP 12). Voltage should be 14 V 1 V. Measure voltage across R831 (TP 7+ and TP 7-). Voltage should be 0.85 V 0.1 V. Measure voltage across R835 (TP 8+ and TP 8-). Voltage should be 0.85 V 0.1 V. Connect negative probe to 0 V (TP 0). Connect positive probe to R849 (TP 10). Voltage should be <5 mV. Connect positive probe to R618 (TP 13). Voltage should be 14 V 1 V. 4.2Functional test procedure For test point (TP) references, see section 6.0 Test Points. 9 4.0 functional tests 4.2Functional test procedure For test point (TP) references, see section 6.0 Test Points. No 4.2.18. 4.2.19. 4.2.20. 4.2.21. 4.2.22. 4.2.23. 4.2.24. 4.2.25. 4.2.26. Action Measure offset of protection circuit Disconnect DC power supplies Fix any faults Connect amplifier to AC power input Measure left channel supply rails Measure right channel supply rails Check operation of mute relay Check preamplifier supply rails Left channel Check power amplifier Test Equipment Multimeter set to mV DC Multimeter set to V DC Multimeter set to V DC Multimeter set to V DC Multimeter set to V DC Multimeter set to V DC Details Connect positive probe to cathode of D943 (TP 11). Voltage should be <5 mV. If any faults have been detected, repair and return to the beginning of this test procedure. Measure volatge across D713 (TP 1+ and TP 1-) and D714 (TP 2+ and TP 2-). Volatge should be 44 V 2.5 V. Measure volatge across D813 (TP 3+ and TP 3-) and D814 (TP 4+ and TP 4-). Volatge should be 44 V 2.5 V. Connect negative probe to 0 V (TP 0). Connect positive probe to cathode of D951 (TP 23). Switch on AC power button. Voltage should increase slowly from 0 to 12 V then relay should operate and voltage should increase to 41 V 2 V. Connect negative probe to 0 V (TP 0). Connect positive probe to 30 V test point (TP 19). Voltage should be 28 V 3 V. Connect positive probe to 10 V test point (TP 15). Voltage should be 10 V 0.5 V. Connect positive probe to 5 V test point (TP 16). Voltage should be 5 V 0.3 V. Measure voltage across R731 (TP 5+ and TP 5-). Voltage should be 0.85 V 0.1 V. Measure voltage across R735 (TP 6+ and TP 6-). Voltage should be 0.85 V 0.1 V. 10 4.0 functional tests 4.2Functional test procedure For test point (TP) references, see section 6.0 Test Points. No 4.2.27. 4.2.28. 4.2.29. 4.2.30. 4.2.31. 4.2.32. 4.2.33. 4.2.34. 4.2.35. 4.2.36. 4.2.37. Action Left channel Measure amplifier offset Left channel Measure preamplifier Right channel Check power amplifier Right channel Measure amplifier offset Right channel Measure preamplifier Measure offset of protection circuit Fix any faults Allow amplifier to warm up Left channel Check bias Right channel Check bias Readjust bias Test Equipment Multimeter set to mV DC Multimeter set to V DC Multimeter set to V DC Multimeter set to V DC Multimeter set to V DC Multimeter set to mV DC Multimeter set to V DC Multimeter set to V DC