QSC-PowerLight3-pwr-sm 维修电路原理图.pdf

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1、Technical Service ManualPowerLight3SeriesPL325PL340PL380*TD-000274-00*TD-000274-00*Rev. AQSC Audio Products, LLCCosta Mesa, CA 92626 USARadioFans.CN 收音机爱 好者资料库RadioFans.CN 收音机爱 好者资料库PL3 Series Service Manual1TD-000274-00 Rev. AQSC Audio Products, LLCTechnical Services GroupPhone:1-800 QSC AUDIO (1-8

2、00-772-2834) USA only+1 (714) 957-7150Fax:+1 (714) 754-6173Postal:1665 MacArthur Blvd.Costa Mesa, California 92626 USAE-mail:tech_Web:http:/ (product information and support)http:/ (parts and accessory sales)PL325PL340PL380PowerLight 3 SeriesTechnical Service ManualCopyright 2008 QSC Audio Products,

3、 Inc. All rights reserved.2QSC Audio Products, LLCPL325 and PL340 amplifier, rear viewPL380 amplifier, rear viewPL3 Series Service Manual3TD-000274-00 Rev. ATable of ContentsTables and Figures.4Specifications.61. Introduction.71.1 Restriction of Hazardous Substances Directive (RoHS). 71.2 Service bu

4、lletins and updates. 71.3 The well-equipped service bench . 71.4 Working with surface-mount components. 81.5 PL380 Service Fixture . 102. Technical Descriptions and Testing .142.1 PL380 Circuit Description . 142.2 PL380 Major Circuit Blocks . 162.3 PL380 Test Procedure . 212.4 PL340 Test and Calibra

5、tion Procedure . 242.5 PL325 Test and Calibration Procedure . 273. Troubleshooting.313.1 PL380: Symptoms, causes, and remedies. 313.2 PL325 and PL340: Symptoms, causes, and remedies. 39PLC Power Supply Restoration Kit . 434. Printed Circuit Boards.534.1 PL325 and PL340 Amplifier . 53Main module circ

6、uit board assembly . 53Input module circuit board assembly . 564.2 PL380 Amplifier . 58Main module circuit board assembly . 585. Schematic Diagrams .645.1 PL325 Schematics . 645.2 PL340 Schematics . 725.3 PL380 Schematics . 806. Replacement parts.896.1 Semiconductor package descriptions and pinouts

7、. 896.2 PL325 parts and assemblies. 93PL325 Power Amplifier (120V) (QSC part # FG-032500-00) . 93PL325 Power Amplifier (100V) (QSC part # FG-032500-01) . 93PL325 Power Amplifier (230V) (QSC part # FG-032500-02) . 93Chassis Assembly PL325 (120V) (QSC part # WP-032500-00) . 93Chassis Assembly PL325 (1

8、00V) (QSC part # WP-032500-01) . 94Chassis Assembly PL325 (230V) (QSC part # WP-032500-02) . 95PCB Assembly PL325 (120V) (QSC part # WP-032501-00). 95PCB Assembly PL325 (100V) (QSC part # WP-032501-01). 98PCB Assembly PL325 (230V) (QSC part # WP-032501-02). 101Input Assembly PL325 (QSC part # WP-032

9、502-00) . 1056.3 PL340 parts and assemblies. 106PL340 Power Amplifier (120V) (QSC part # FG-034000-00) . 106PL340 Power Amplifier (100V) (QSC part # FG-034000-01) . 106PL340 Power Amplifier (230V) (QSC part # FG-034000-02) . 106Chassis Assembly PL340 (120V) (QSC part # WP-034000-00) . 106Chassis Ass

10、embly PL340 (100V) (QSC part # WP-034000-01) . 107Chassis Assembly PL340 (230V) (QSC part # WP-034000-02) . 108PCB Assembly PL340 (120V) (QSC part # WP-034001-00). 108PCB Assembly PL340 (100V) (QSC part # WP-034001-01). 112PCB Assembly PL340 (230V) (QSC part # WP-034001-02). 115Input Assembly PL340

11、(QSC part # WP-034002-00) . 1186.4 PL380 parts and assemblies. 120PL380 Power Amplifier (120V) (QSC part # FG-038000-00) . 120PL380 Power Amplifier (100V) (QSC part # FG-038000-01) . 120PL380 Power Amplifier (230V) (QSC part # FG-038000-02) . 1204QSC Audio Products, LLCTables and FiguresChassis Asse

12、mbly PL380 (120V) (QSC part # WP-038000-00) . 120Chassis Assembly PL380 (100V) (QSC part # WP-038000-01) . 121Chassis Assembly PL380 (230V) (QSC part # WP-038000-02) . 122PCB Assembly PL380 (120V) (QSC part # WP-038001-00) through January 2008 . 122PCB Assembly PL380 (100V) (QSC part # WP-038001-01)

13、 through January 2008 . 126PCB Assembly PL380 (230V) (QSC part # WP-038001-02) through January 2008 . 130PCB Assembly PL380 (120V) (QSC part # WP-038001-00) from February 2008 . 134PCB Assembly PL380 (100V) (QSC part # WP-038001-01) from February 2008 . 138PCB Assembly PL380 (230V) (QSC part # WP-03

14、8001-02) from February 2008 . 142Table of Contents (continued)PL325 and PL340 amplifier, rear view. 2PL380 amplifier, rear view. 2Table 1.1. Load resistor bank switch truth table. 7Figure 1.1. Load resistor bank . 7Figure 1.2. Use two irons. 8Figure 1.3. Soak up solder. 8Figure 1.4. Apply new solder

15、. 8Figure 1.5. Place component . 8Figure 1.6. Solder one end of the component. 8Figure 1.7. Solder other end. 8Figure 1.8. The PL380 service fixture . 10Figure 1.9. Locations of Test Point A and Test Point B. 10Figure 1.10. Jumpers to be removed from Test Point B. 11Figure 1.11. Connecting the hooku

16、p leads. 11Figure 1.12. Schematic diagram of the PL380 service fixture . 12Figure 1.13. Proper IGBT drive signals (with chassis ground reference ) . 13Figure 1.14. Proper FET gate drive signals with FETs installed (with chassis ground reference) . 13Figure 2.1. Signal with 250 kHz switching noise .

17、21Figure 2.2. Signal with switching noise filtered out. 21Figure 2.3. Burst sine wave signal for 2 power testing. 21Figure 2.4. Noise and distortion residual with bias properly set. 25Figure 3.1 IGBT gate drive waveforms. 32Figure 3.2 FET gate drive waveforms. 33Figure 3.3 Dead time between one puls

18、e turning off and the other turning on should be about 2030 ns at the 5 V level. 33Figure 3.4 The clock drive logic signals. 33Figure 3.5 The power supply sync pulse. . 34Figure 3.6 Triangle wave at comparator inputs (pin 2 of U8 and U28). . 35Figure 3.7 Triangle wave with supply rails energized. 35

19、Figure 3.8. Switching pulse at node N401 (pin 3 of U19) . 39Figure 3.9: Switching signal with dead time at nodes N397 and 398 (pins 11 and 14 of U19). 40Figure 3.10. Typical crossover residual from distortion analyzer output . 41Figure 3.11. Identify damaged transistors by measuring resistance acros

20、s the collector and emitter. . 43Table 3.1. Clamping voltage troubleshooting . 44Table 3.2. Troubleshooting clamp malfunctions . 45Figure 3.12. The overcurrent detection circuit for power supply cutback. . 46Table 3.3. Troubleshooting clamp transistors . 46PL3 Series Service Manual5TD-000274-00 Rev.

21、 ATable 3.4. Troubleshooting short circuit cutback clamping. 47Figure 3.13. Output signal and positive rail steps. . 48Figure 3.14. Output signal and negative rail steps. . 48PL325 and PL340 main circuit board, with major circuit sections shown . 53PL325 and PL340 main circuit board, top layer. 54PL

22、325 and PL340 main circuit board, bottom layer, mirror image . 55PL325 and PL340 input board, top layer . 56PL325 and PL340 input board, bottom layer, mirror image. 57PL380 main circuit board, with major circuit sections shown . 58PL380 main circuit board, detailed view. 59PL380 input board, main ci

23、rcuit blocks shown. 59PL380 main circuit board, top layer. 60PL380 main circuit board, mid1 layer. 61PL380 main circuit board, mid2 layer. 62PL380 main circuit board, bottom layer . 63PL325 schematic notes. 64Schematic sheet INPUT, PL325 . 65PL325 wiring diagram. 66PL325 schematic guide. 67Schematic

24、 sheet AMP CH-A, PL325. 68Schematic sheet AMP CH-B, PL325. 69Schematic sheet PROTECT/CONTROL, PL325 . 70Schematic sheet POWER SUPPLY, PL325 . 71PL340 schematic notes. 72Schematic sheet INPUT, PL340 . 73PL340 wiring diagram. 74PL340 schematic guide. 75Schematic sheet AMP CH-A, PL340. 76Schematic shee

25、t AMP CH-B, PL340. 77Schematic sheet PROTECT/CONTROL, PL340 . 78Schematic sheet POWER SUPPLY, PL340 . 79PL380 schematic notes. 80PL380 wiring diagram. 81PL380 schematic guide. 82Schematic sheet AMP CH-A, PL380 through January 2008. 83Schematic sheet PROTECT/CONTROL, PL380 . 84Schematic sheet AMP CH-

26、B, PL380 through January 2008 . 85Schematic sheet POWER SUPPLY, PL380 through January 2008. 86Schematic sheet INPUT, PL380 through January 2008 . 87Schematic sheet AMP CH-A, PL380 from February 2008. 88Schematic sheet AMP CH-B, PL380 from February 2008. 89Schematic sheet POWER SUPPLY, PL380 from Feb

27、ruary 2008. 90Schematic sheet INPUT, PL380 from February 2008 . 91Tables and Figures (continued)6QSC Audio Products, LLCPL325PL340PL380Stereo Mode (both channels driven)8 / EIA 1 kHz / 1% THD4 / EIA 1 kHz / 1% THD2 / EIA 1 kHz / 1% THD500 W850 W1250 W800 W1250 W2000 W1500 W2500 W4000 W*Bridge Mono M

28、ode8 / EIA 1 kHz / 1% THD4 / EIA 1 kHz / 1% THD1700 W2500 W2600 W4000 W5000 W8000 W*Typical Distortion(20 Hz20 kHz, 3 dB below clip, or20 Hz5 kHz, 10 dB below clip, or20 Hz20 kHz, 20 dB below clip)8420.0020.01%0.0050.01%0.02%0.0020.01%0.0050.01%0.02%0.010.03%0.030.06%0.10%Maximum Distortion(20 Hz20

29、kHz, 1 dB below rated power)48 0.05%0.05%0.20%Frequency Response (8) 20 Hz20 kHz, 0.2 dB20 Hz20 kHz, 0.2 dB20 Hz20 kHz, 0.2 dBNoise (20 Hz20 kHz, 32 dB gain) -106 dB-105 dB-104 dBDynamic Headroom (4) 2 dB2 dB2 dBDamping Factor (8) 500500200Output Circuitry Class H (2-tier)Class H (2-tier)Class DInpu

30、t Sensitivity max gain(26 dB setting)(32 dB setting)3.28 V (+12.5 dBu)1.60 V (+6.3 dBu)3.92 V (+14 dBu)1.96 V (+8.1 dBu)5.27 V (+16.7 dBu)2.67 V (+10.7 dBu)Maximum Gain (1.2 V setting) 34.5 dB36.4 dB39.1 dBInput Impedance 10 k, balanced or unbalanced10 k, balanced or unbalanced10 k, balanced or unba

31、lancedMaximum Input Level(1.2 V setting)(32 dB setting)(26 dB setting)11 V (+23 dBu)14.6 V (+25.5 dBu)25 V (+30 dBu)11 V (+23 dBu)14.6 V (+25.5 dBu)25 V (+30 dBu)10 V (+22 dBu)22 V (+29 dBu)25 V (+30 dBu)Controls and LEDsFront Panel Common: AC Power Switch, Power LED (blue), Br Mono LED (yellow), Pa

32、r LED (orange)Each Channel: Signal -35 dB LED (green), -20 dB LED (green), -10 dB LED (orange), Clip/Prot LED (red),Gain Control (21 detents, 1 dB steps)Controls and LEDsRear Panel Common: Input Mode Parallel LED (orange), Stereo LED (green), Br Mono LED (yellow); Sensitivity 26 dBLED (orange), 32 d

33、B LED (green), 1.2 V LED (yellow)Each Channel: LF Filter Switch off30 Hz (yellow LED)50 Hz (red LED); Clip Limiter Switch offon (yellow LED)Input Connectors Common: HD15 DataPort (inputs parallel with XLR inputs)Each Channel: Male XLR, Female XLR, 3-Pin Terminal BlockOutput Connectors Each Channel:

34、5-Way Binding Posts, Neutrik Speakon (upper has both channel outputs)Amplifier and Load Protection Short circuit, open circuit, thermal, RF protection. On/off muting, DC fault shutdown, active inrush current limitingAC Power* / Cordset120 V, 5060 Hz230 V 50 Hz8.5 A / NEMA-157.5 A / Euro 16 A12 A / N

35、EMA-157 A / Euro 16 A18 A / L5-30 (30 A twist-lock)11 A / Euro 16 ADimensions Height: 2 RU 3.5 (8.9 cm); Width: 19 (48.3 cm); Depth: 15.63 (39.7 cm) from front mounting railsWeight Net / Shipping 22 lb (10 kg) / 31.5 lb (14.3 kg)22 lb (10 kg) / 31.5 lb (14.3 kg)24 lb (11 kg) / 33.5 lb (15.2 kg)Agenc

36、y Approvals UL, CE, RoHS / WEEE compliant, FCC Class B (conducted and radiated emissions)* Burst mode testing required due to AC service current limitations* Representative of current draw with tyical music program material with occasional clippingAll specifications are subject to change without not

37、ice.SpecificationsPL3 Series Service Manual7TD-000274-00 Rev. AFigure 1.1. Load resistor bankTable 1.1. Load resistor bank switch truth table1. Introduction1.1 Restriction of Hazardous Substances Directive (RoHS)All PowerLight 3 Series amplifiers are manufactured to conform to the European Unions Ro

38、HS Directive, which reduces the amount ofhazardous substances allowed in products for sale within its member nations. In electronic equipment such as audio power amplifiers, thisapplies primarily to certain toxic heavy metals, such as lead, which may be present in electronic components, solder, and

39、other parts.RoHS-compliant materialsWhen servicing RoHS-compliant amplifiers, it is important for the service technician to use only RoHS-compliant components and solder(lead-free). All replacement parts provided by QSC for RoHS-compliant products are certified as RoHS compliant.RoHS-compliant tools

40、Soldering irons and desoldering apparatus used on RoHS-compliant products must also not be contaminated by hazardous substances, suchas lead. Therefore, you cannot use the same soldering and desoldering tools for RoHS-compliant products and solder as you do for non-compliant products and solder. You

41、 must either use separate soldering irons, desoldering tools and braid, etc., or at the very least designateseparate tips and braids and use only the appropriate ones. If you contaminate a tip or braid, even inadvertently, by using it on a non-compliant product or solder, you can no longer use it wi

42、th RoHS-compliant products or solder.1.2 Service bulletins and updatesContact QSC Technical Services to make sure you have the most up-to-date service bulletins, schematics, and parts lists for PowerLight 3Series amplifiers. Service materials may be distributed in hard copy, via fax, and electronica

43、lly (Adobe Acrobat PDF) via CD-ROMs, FTP fromthe QSC web site (), and e-mail.At the time of this manuals publication, one service bulletin, PL30001 (PL380 and Standby), had been released for the PowerLight 3amplifiers.1.3 The well-equipped service benchTo properly service PowerLight 3 amplifiers, a

44、technician needs the right tools. Thetechnicians service bench should have the following equipment: Digital multimeter with RMS AC voltage and current Digital clamp-on ammeter Dual-trace oscilloscope Low-distortion audio sine wave generator Audio distortion analyzer Switching amplifier measurement f

45、ilter, such as Audio Precision AUX-0025 Bank of non-inductive load resistors, configurable as 8 ohms(min. 1500 watts capacity), as 4 ohms (min. 3000 watts), and 2 ohms(min. 4000 watts). See Figure 1.1. Variable AC voltage source, such as a Variac or Powerstatvariable transformer;For PL325 and PL340:

46、 rated current capacity of up to 25 A (for120 V models) or 12 A (for 230 V models)For PL380: rated current capacity of up to 50 A (for 120 V models)or 25 A (for 230 V models) Philips and flat screwdriversSW1SW2SW3SW48888R1, R2: 8 , 1500W non-inductiveR3, R4: 8 , 1000W min. non-inductiveR1R2R3R4SW1SW

47、2SW3SW4 (no load)OFF8 ONOFFOFFOFF4 ONONOFFOFF2 ONONONOFF0 (short circuit)ONON8QSC Audio Products, LLCFigure 1.6. Solder one endof the componentFigure 1.7. Solder otherendFigure 1.5. PlacecomponentFigure 1.4. Apply newsolderFigure 1.3. Soak up solderFigure 1.2. Use two ironsSolder braid Soldering iro

48、n with a fine tip (2560 W recommended) RoHS-compliant rosin-core solder Long-nose pliers Diagonal cutters Wire strippers PL380Automated test equipment, such as an Audio Precision workstation, is very useful for servicing QSC amplifiers.Contact QSC Technical Services to obtain applicable AP test file

49、s.1.4 Working with surface-mount componentsPowerLight 3 amplifiers, like many modern electronic products, use surface-mount technology (SMT) compo-nents where appropriate in order to make high-density circuitry that is reliable and economical to manufac-ture.SMT components are used in the amplifiers

50、 small-signal and control circuits, so they do not handle significantamounts of power; therefore, they are subject to very little stress and should seldom fail. Sometimes they dofail, or they require replacement for a performance upgrade or modification. Thus, it is important to know howto work with