QSC-RMXseriesC-pwr-sm 维修电路原理图.pdf

Technical Service ManualRMX Series2RU modelsRMX 850RMX 1450RMX 1850HDRMX 2450*TD-000098-00*TD-000098-00Rev. CQSC 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RMX Series Technical Service Manual (2RU models)1TD-000098-00 rev. CQSC Audio Products, LLCTechnical Services GroupPhone:1-800 QSC AUDIO (1-800-772-2834) 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)RMX 850RMX 1450RMX 1850HDRMX 2450RMX SeriesTechnical Service ManualCopyright 2001, 2002, 2005, 2008 QSC Audio Products, LLC All rights reserved.Document # TD-000098-00, Rev. C. Released June 2008.2QSC Audio Products, LLCRMX 850RMX 1450RMX 1850HDRMX 2450OUTPUT POWER in wattsFTC: 20 Hz20 kHz 0.1% THD, both channels driven8 per channel1852603504504 per channel280400550650EIA: 1 kHz 0.1% THD, both channels driven8 per channel2002803605004 per channel3004506007501 kHz 1% THD, typical, both channels driven2 per channel4307009001200Bridge Mono:8, 20 Hz20 kHz, 0.1% THD53080013008, 1 kHz, 0.1% THD600900120015004, 1 kHz, 1% THD, typical830140018002400DYNAMIC HEADROOM2 dB 4DISTORTIONSMPTE-IM 0.01% 0.01% 0.02% 300 8NOISE (unweighted 20 Hz to 20 kHz, below rated output)100 dB100 dB100 dB100 dBVOLTAGE GAIN31.6 (30 dB)40 (32 dB)46 (33 dB)50 (34 dB)INPUT SENSITIVITY, V RMSfull rated power 81.15v (+3.4 dBu)1.15v (+3.4 dBu)1.16v (+3.5 dBu)1.23v (+4.0 dBu)INPUT IMPEDANCE10 k unbalanced20 k balancedCONTROLSFront: AC switch, Ch. 1 and Ch. 2 gainRear: 10-position DIP switchINDICATORSPOWER:Green LEDCLIP:Red LED, 1 per channelSIGNAL:Yellow LED, 1 per channelCONNECTORSInput:Active balanced; XLR and (6.3 mm) TRS, tip and pin 2 positive, and barrier stripOutput:“Touch-Proof” binding posts and Neutrik SpeakonCOOLINGContinuously variable speed fan, back-to-front air flowAMPLIFIER PROTECTIONFull short circuit, open circuit, thermal, ultrasonic, and RF protectionStable into reactive or mismatched loadsLOAD PROTECTIONTurn-on/turn-off muting (all models)AC couplingAC couplingTriac crowbar (each channel)Triac crowbar (each channel)OUTPUT CIRCUIT TYPEABABHHAB: Class AB+B complementary linear outputH: Class AB+B complementary linear output with Class H 2-step high efficiency circuitDIMENSIONS19.0 (48.3 cm) wide, 3.5 (8.9 cm) tall (2 rack spaces)15.9 (40 cm) deep (rack mounting to rear support ears)WEIGHTShipping:41 lb. (18.6 kg)46 lb. (20.9 kg)50.5 lb. (23 kg)50.5 lb. (23 kg)Net:35 lb. (15.9 kg)40 lb. (18.2 kg)44.5 lb. (20.2 kg)44.5 lb. (20.2 kg)POWER REQUIREMENTSAvailable for 120 or 220240 VAC, 50/60 HzPOWER CONSUMPTION 120 VAC(both channels driven)Multiply currents by 0.5 for 230V unitsl ac i pyT1l l uF2xaM3e l d IA5 . 08 A3A1 . 4A4 . 74 A5 . 4A6 . 6A5 . 112 A5 . 6*A5 . 9*A71l ac i pyT1l l uF2xaM3e l d IA5 . 08 A7 . 3A4 . 5A014 A6A6 . 9A612 A3 . 9*A7 . 41*A52l ac i pyT1l l uF2xaM3e l d IA6 . 08 A4A7 . 9A4 . 614 A3 . 6A6 . 51A722 A2 . 9*A32*A14RMX Series Performance SpecificationsTypical1Full2Max3Idle0.8 A8 3.9 A6.9 A12.6 A4 6.1 A11.2 A20.7 A2 8.7 A16.6 A*32 A*1. TypicalMeasured with pink noise signal on all channels at 1/8 of full average power. Producing peaks that occasionally reach the amps clipping point, this level approximates the maximum operatinglevel before clipping affects sound quality. These data would be the amps typical worst-case current.2. FullMeasured with pink noise signal on all channels at 1/3 of full average power. Music at this level would typically produce massive clipping. In a class B amplifier, this would be the approximatepoint of maximum heat production.3. MaxMeasured with continuous sine wave signal on all channels at a point of slight clipping (1% THD). This represents a “test bench” scenario and does not resemble any real-world usage.US patents pendingSPECIFICATIONS SUBJECT TO CHANGE WITHOUT NOTICERMX Series Technical Service Manual (2RU models)3TD-000098-00 rev. CTable of ContentsRMX Series Performance Specifications. 21. Introduction . 51.1 Restriction of Hazardous Substances Directive (RoHS). 51.2 QSC serial numbers . 51.3 Service bulletins. 51.4 The well-equipped service bench. 61.5 Working with surface-mount components . 61.6 Series description . 81.7 Technical descriptions and theory of operation . 82. Component identification and pinout . 113. Troubleshooting: Symptoms, causes, & remedies. 133.1 Excessive current draw . 133.2 Protection, muting, and turn-on/turn-off delay problems . 133.3 Faults with signal present . 143.4 Instability. 143.5 Power supply and rail balancing problems . 154. RMX calibration procedures. 164.1 Setting bias . 164.2 Setting positive and negative current limits . 165. Servicing RMX amplifiers . 185.1 Mechanical disassembly and re-assembly. 186. Replacement parts . 196.1 RMX850 Replacement Parts . 196.2 RMX1450 Replacement Parts . 226.3 RMX1850HD Replacement Parts. 256.4 RMX2450 Replacement Parts . 297. Schematics and diagrams . 337.1 RMX Assembly/Disassembly Diagram 1 of 2(All models). 337.2 RMX Assembly/Disassembly Diagram 2 of 2(All models). 347.3 RMX 850 Schematic Diagram 1 of 3Channel 1 . 357.4 RMX 850 Schematic Diagram 2 of 3Channel 2 . 367.5 RMX 850 Schematic Diagram 3 of 3Power Supply . 377.6 RMX 1450 Schematic Diagram 1 of 3Channel 1 . 387.7 RMX 1450 Schematic Diagram 2 of 3Channel 2 . 397.8 RMX 1450 Schematic Diagram 3 of 3Power Supply . 407.9 RMX 1850HD Schematic Diagram 1 of 3Channel 1 . 417.10 RMX 1850HD Schematic Diagram 2 of 3Channel 2 . 427.11 RMX 1850HD Schematic Diagram 3 of 3Power Supply . 437.12 RMX 2450 Schematic Diagram 1 of 4Channel 1 . 444QSC Audio Products, LLC7.13 RMX 2450 Schematic Diagram 2 of 4Channel 2 . 457.14 RMX 2450 Schematic Diagram 3 of 4Power Supply . 467.15 RMX 2450 Schematic Diagram 4 of 4Power Supply Revision . 477.16 RMX Power Transformer ConfigurationsMarch 2007 and later . 487.17 RMX 850 Chassis Wiring Diagram. 497.18 RMX 1450 Chassis Wiring Diagram. 507.19 RMX 1850HD and RMX 2450 Chassis Wiring Diagram . 51Table of Contents (continued)RMX Series Technical Service Manual (2RU models)5TD-000098-00 rev. C1. Introduction1.2 QSC serial numbersSerial numbers on QSC RMX series amplifiers are nine digits long. The firstfour digits are a manufacturing date code in mmyy format; the last five digitsare the sequential identifying number for each individual amplifier. Forexample, a serial number of 0807xxxxx would indicate that the amplifier wasbuilt in 08/2007, or August 2007. The date code is important for determiningwhether an amplifier is subject to a service bulletin, covered by a warranty (inthe absence of original purchase records), etc.The amplifiers serial number can be found on a label on the rear panel. Thelabel also indicates the model number, power rating, 4 current draw, and theAC mains voltage the amplifier was made for.Certain design changes that the RMX amplifiers have undergone commencedwith a particular date code; for example, the RMX amplifiers with a date codeof 0406 or later conform to the European Unions RoHS Directive and must beserviced only with lead-free solder and soldering irons that are not contami-nated with lead or other heavy metals covered by the directive.1.1 Restriction of Hazardous Substances Directive (RoHS)Since April 2006, all RMX Series amplifiers are manufactured to conform to the European Unions RoHS Directive, which reduces theamount of hazardous substances allowed in products for sale within its member nations. In electronic equipment such as audio poweramplifiers, this applies primarily to certain toxic heavy metals, such as lead, which may be present in electronic components, solder, andother 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 toolsSoldering irons and desoldering apparatus used on RoHS-compliant products must also not be contaminated by hazardous substances,such as lead. Therefore, you cannot use the same soldering and desoldering tools for RoHS-compliant products and solder as you do fornon-compliant products and solder. You must either use separate soldering irons, desoldering tools and braid, etc., or at the very leastdesignate separate tips and braids and use only the appropriate ones. If you contaminate a tip or braid, even inadvertently, by using it ona non-compliant product or solder, you should no longer use it with RoHS-compliant products or solder.1.3 Service bulletinsContact QSC Technical Services to make sure you have the most up-to-date service bulletins for RMX Series amplifiers. Service bulletinsmay be distributed in hard copy, via fax, and electronically (Adobe Acrobat PDF) via CD-ROMs, FTP from the QSC web site(), and e-mail.These service bulletins had been issued at the time this manual was printed: RMX0001, “Q205 Lead Stress” (RMX2450 only) RMX0002, “RMX Turn-on Delay” (all RMX models) RMX0003, “RMX2450 Turn-off Mute” (RMX2450) RMX0004, “RMX2450 AC Wire Routing” (RMX 2450) RMX0005, “RMX2450 AC Wire Replacement” (RMX2450) RMX0006, “RMX2450 IRFZ44N Field Effect Transistors (RMX2450)Figure 1.1. The label displays two vital pieces ofinformation: the amplifiers serial number andoperating voltage6QSC Audio Products, LLCSolder1.4 The well-equipped service benchTo properly service RMX amplifiers, a 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 Audio distortion analyzer Non-inductive load resistors, configurable as 8 ohms (min. 500 watts capacity),as 4 ohms (min. 750 watts capacity), and 2 ohms (min. 1200 watts capacity);see Figure 1.2 and Table 1.1. Variable AC voltage source, such as a Variac or Powerstat variable trans-former, with a rated current capacity of up to 25A (for 120V models) or 12A (for230V models) Low-distortion audio sine wave generator Philips and flat screwdrivers Soldering iron with a fine tip, 2560W recommended (if youservice both RoHS-compliant and non-compliant amplifiers, youwill need separate soldering and desoldering equipment foreach) Appropriate rosin-core solder (use only RoHS compliant lead-free solder for RoHS-compliant amplifers; for non-RoHSamplifiers, use a 60/40 or 63/37 Pb/Sn alloy) Long-nose pliers Diagonal cutters Wire strippersAutomated test equipment, such as an Audio Precision workstation, is very useful for servicing RMX amplifiers. Contact QSC TechnicalServices to obtain applicable AP test files.Solder braid1.5 Working with surface-mount componentsRMX amplifiers, like many modern electronic products, use surface-mount technology (SMT) componentswhere appropriate in order to make high-density circuitry that is reliable and economical to manufacture.SMT components in the RMX amps are used in the small-signal and control circuits, so they do not handlesignificant amounts of power; therefore, they are subject to very little stress and should seldom fail.Sometimes they do fail, or they require replacement for a performance upgrade or modification. Thus, it isimportant to know how to work with SMT components.Specialized tools and equipment exist for soldering, unsoldering, and removing SMT components quicklyand efficiently, but they are often expensive. Most SMT repairs, though, can be handled reasonably well withcommon tools and equipment, such as tweezers, solder braid, and fine-tip soldering irons. The originalfactory components are tacked to the board with a spot of glue, so you might have to apply some force tobreak the adhesive.Two-terminal components (resistors, capacitors, diodes, etc.)Removal1 Use two soldering irons, preferably about 25 to 40 watts, with fine tips.2 With a soldering iron in each hand, hold one tip on the solder at one end of the component and theother tip on the other end (Figure 1.3).3 Once the solder melts on both ends, grip the component between the two tips and lift it from thecircuit board.4 Use solder braid and a soldering iron to remove the solder from the two pads (Figure 1.4).Figure 1.2. Load resistor bankTable 1.1. Load resistor bank switch truth tableSW1SW2SW3SW48888R1: 8 , 500W non-inductiveR2R4: 8 , 300W min. non-inductiveR1R2R3R4SW1SW2SW3SW4 (no load)OFF8 ONOFFOFFOFF4 ONONOFFOFF2 ONONONOFF0 (short circuit)ONONFigure 1.5.Figure 1.3.Figure 1.4.RMX Series Technical Service Manual (2RU models)7TD-000098-00 rev. CSolderTweezersSolderInsertion1 With a soldering iron and appropriate solder, melt just enough solder onto one pad to create a smallmound (Figure 1.5).2 Grasp the component in the middle with tweezers. Melt the small mound of solder with the iron andplace the component across the two pads (in the correct orientation, if the component is sensitive todirection) and press it flat against the circuit board, with one end of the component immersed in themelted solder (Figure 1.6).3 Hold the component in place and take the soldering iron away. Let the solder harden to tack thecomponent in place.4 Fully solder the other end of the component to its pad. Let the solder harden (Figure 1.7).5 Fully solder the tacked end of the component to its pad (Figure 1.8).3 When the solder on both ends melts, grip the component between the two tips and lift it from the circuit board. You might need toquickly touch the pad on the middle terminal with a soldering iron to melt any remaining solder that might be holding the componentdown.4 Use solder braid and a soldering iron to remove the solder from the three pads.Insertion1 With a soldering iron and appropriate solder, melt just enough solder onto one pad to create a small mound of solder.2 Grasp the component with tweezers. Melt the small mound of solder with the iron and place the component in the correct orientationacross the three pads and press it flat against the circuit board, with one terminal of the component pressed into the melted solder.3 Hold the component in place and take the soldering iron away. Let the solder harden to tack the component in place.4 Fully solder the other terminals of the component to their pads. Let the solder harden.5 Fully solder the tacked terminal of the component to its pad.Multi-pin components (ICs, etc.)RemovalRemoving a multi-pin SMT component is a delicate procedure. Ideally, you should use a soldering iron with an attachment that allows youto heat all the pins simultaneously.If such a soldering device is not available, use this procedure:1 Use a soldering iron and solder braid to remove as much solder as possible from the pins of the component.2 With fine tweezers, carefully try to lift each pin to see if its free. If its not, touch it with the tip of the soldering iron and if necessary,use the solder braid to remove the remaining solder.3 Repeat the process until all the pins are free and you can remove th