QSC PLX-1202 Wartungshandbuch

Technical Service ManualPLX™ Series▲▲▲▲▲ PLX 1202▲▲▲▲▲ PLX 1602▲▲▲▲▲ PLX 2402▲▲▲▲▲ PLX 3002TD-000078-00TD-000078-00

3. Turn the power switch off and on a few times to verify the 3 second power-up mutingdelay.. CHANNEL OUTPUT1. Look for amplified signal on the scope

l FREQUENCY RESPONSEI. Set load to 8 ohms and scale the input generator to gain 1 watt of power from theamplifier on each channel. Gain controls on th

3. Connect a distortion analyzer with a resolution of O.Ol%, 20-20kHz (or better) to theoutput terminals of the amplifier. Enable the 80kHz low pass f

disable the 80kHz lowpass filter on the analyzer for this test.Further trim so thatthe total distortion for that channel is less than 0.1% THD+N,3. Wi

l OUTPUT NOISE1. Set the amplifier gain controls all the way up, with a I kHz 1.5OVrms sinewave inputsignal.Note the output level at full power just b

2. Select an 8 ohm load and confirm that this amplifier is producing 550 watts at 1 kHz justbelow the point of clipping. Check both channels.l BRIDGE

l POWER vs. DISTORTION TEST1. Check to ensure that both channels will produce rated power at 2OH2, 2KHz, and 20kHz.into an 8 ohm load.2. While verifyi

T r o ubleshootingPLX 1202 l PLX 1602 l PLX 2402 l PLX 3002Power Supply - -Replacing Blown IGBTs.In order to improve EMI performance, reduce cost, and

Troubleshooting “TOP-210” Bias Supply.QUICK TEST OF BIAS SUPPLY.Ramp the AC voltage up slowly to 25% of regular voltage (30V for 12OV unit). If the bi

CHECK EMITTER AND BASE RESISTORS WHILE DEVICES ARE REMOVED,Each output transistor has an associatated pair of 0.47 ohm resistors in parallel.Each BANK

+ PLX 1202+ PLX 1602+ PLX 2402+ PLX 3002

Audio Power Stage, Current Limit TroubleshootingCURRENT LIMITS WHICH COLLAPSE PREMATURELY.An immediate collapse of ALL current limits at full power co

CLAMPING VOLTAGE DECREASES, BUT NO CURRENT CUTBACKCHANNEL-POLARITY CH I+ CH l- CH 2+ CH 2-Measure voltage on: c21 c22C56C5?Check clamp transistor Q18

Audio Output, Troubleshooting Stability FeedbackHIGH FREQUENCY OSCILLATIONSSEVERE-DRAWS CURRENT-GROSS DISTORTIONC27 (62) missing or wrong, or series R

CLIP LIMITING DOESN’T WORK:BOTH CHANNELS:Check U3 missing,Check U3 supply voltages, +I 3VCL, -13VCL, on C73* 74ONLY ONE CHANNEL BAD:Probe output of U2

Step Chattering.If the step repeatedly switches on and off, usually at a low frequency, it creates an oscillation burstwhich increases step glitch at

FET Turns On or Off Very Slowly:Generally causes problems at high frequency, 2 ohms.If both slopes are equally slow, check the slope capacitors:Positi

Fan Speed TroubleshootingFAN STUCK HIGH:Q88 or Q89 failedR30 or Rl55, Thermal Sense NTC, shorted to heatsinkR266 or R271 missing.FAN DOESN’T RUNCheck

PLX 1202 PCB ASSEMBLY (12OV) PLX 1202 PCB ASSEMBLY (12OV) Cont’dPart Number Description ReferenceCA-01 0002-30 CAP 1 OPF 5% 50V 0805 SMT c14,49CA-01 5

PLX 1202 PCB ASSEMBLY (12OV) Cont’d PLX 1202 PCB ASSEMBLY (12OV) Cont’dPart Number Description Reference Part Number Description ReferenceQ70,89,90,Q9

PLX 1202 PCB ASSEMBLY (12OV) Cont’d PLX 1202 PCB ASSEMBLY (12OV) Cont’dPart NumberDescription Reference Part Number Description ReferenceRE-212702-30R

PLX SERIESSERVICE MANUALPLX 1202PLX 1602PLX 2402PLX 3002QSC Technical ServicesWats: I -%OO-772-2034Local: 1-714-957-7150Fax: 1-714-754-6173QSC Technic

PLX 1202 PC6 ASSEMBLY (230V) Cont’d PLX 1202 PCB ASSEMBLY (230V) Cont’dPart Number Description ReferencePart NumberDescriptionReferenceCA-610002-10 lO

PLX 1202 PCB ASSEMBLY (230V) Cont’d PLX 1202 PCB ASSEMBLY (230V) Cont’dPart Number Description Reference Part Number Description ReferenceRE-00021 O-N

PLX 1202 PCB ASSEMBLY (230V) Cont’d PLX 1202 CHASSIS ASSEMBLY (230V)Part Number DescriptionReferencePart Number DescriptionReferenceSW-000029-S RELAY,

PLX 1602 PCB ASSEMBLY (12OV) Cont’dPLX 1602 PCB ASSEMBLY (12OV) Cont’dPart Number Description ReferenceCl56,157C28,63,CA-410006-30 CAP CER .lUF 10% 5O

PLX 1602 PCB ASSEMBLY (12OV) Cont’d PLX 1602 PCB ASSEMBLY (12OV) Cont’dPart Number Description Reference Part Number Description ReferenceQD-001302-PN

PLX 1602 PCB ASSEMBLY (12OV) Cont’dPLX 1602 PCB ASSEMBLY (230V)Part Number DescritdionReferenceRE-220003-30RES SMT 2O.OK 1% 1/8W 1206Rl72,173R49,50,RE

PLX 1602 PCB ASSEMBLY (230V) Cont’dPLX 1602 PCB ASSEMBLY (230V) Cont’dPart Number Description ReferenceCl59,160,Cl65166,Cl69,170,c173,174CA-822200-AE

PLX 1602 PCB ASSEMBLY (230V) Cont’d PLX 1602 PCB ASSEMBLY (230V) Cont’dPart NumberDescriptionReferenceRa5-a7,90xR93,2oa,RE-003921-30 RES SMT 39.2 OHM

PLX 1602 PCB ASSEMBLY (230V) Cont’dPLX 1602 CHASSIS ASSEMBLY (230V)Part Number Description ReferenceREF:D87,88WC-000001-10 JUMPER INS .6” 22AWG SOLID

PLX 2402 PCB ASSEMBLY (12OV)PLX 2402 PCB ASSEMBLY (12OV) Cont’dPart NumberDescridionReferenceCA-01 0002-30CAP 1 OPF 5% 5OV 0805 SMTc14,49CA-01 5002-10

Table of ContentsPLX Product Specifications ...Introduction ...

PLX 2402 PCB ASSEMBLY (12OV) Cont’dPLX 2402 PCB ASSEMBLY (12OV) Cont’dPart Number Description Reference Part Number DescriptionReferenceQ86QD-000042-0

PLX 2402 PCB ASSEMBLY (12OV) Cont’dPLX 2402 PCB ASSEMBLY (12OV) Cont’dPart NumberDescriptionRE-082001-10 RES MOFP 820 5% 2W MINIRE-I10006-30RESSMT1.OO

PLX 2402 PCB ASSEMBLY (12OV) Cont’d PLX 2402 PCB ASSEMBLY (230V) Cont’dPart NumberDescriutionReferencePart Number Description ReferenceWC-0001 17-03SP

PLX 2402 PCB ASSEMBLY (230V) Cont’d PLX 2402 PCB ASSEMBLY (230V) Cont’dPart NumberDescriptionReferencePart Number Description ReferenceIC-005532-OPMS-

PLX 2402 PCB ASSEMBLY (230V) Cont’d PLX 2402 PCB ASSEMBLY (230V) Cont’dPart Number Description Reference Part Number Description ReferenceRE-010002-30

PLX 2402 PCB ASSEMBLY (230V) Cont’dPLX 2402 CHASSIS ASSEMBLY (230V)Part NumberDescriotionReferencePart NumberDescription ReferenceRE-375005BMSC-0631 0

PLX 3002 PCB ASSEMBLY (12OV)PLX 3002 PCB ASSEMBLY (12OV) Cont’dPart NumberDescriDtionReference Part Number Description ReferenceCA-01 0002-30CA-01 500

PLX 3002 PCB ASSEMBLY (12OV) Cont’dPLX 3002 PCB ASSEMBLY (12OV) Cont’dPart NumberDescriptionReferenceRl55,LDl,REF.R30,PL-000135-00INSULATOR, MICA 1.25

PLX 3002 PCB ASSEMBLY (12OV) Cont’dPLX 3002 PCB ASSEMBLY (12OV) Cont’dPart NumberDescription ReferencePart Number Description ReferenceRE-015004-10 RE

PLX 3002 PCB ASSEMBLY (12OV) Cont’d PLX 3002 PCB ASSEMBLY (230V) Cont’dPart NumberDescription ReferenceR335,341,R342,343R52,54,57,R5a,l75!RE-339201-30

PLX Product SpecificationsPLX 1202PLX 1602PLX 2402PLX 3002PLXI 202PLXI 602PLX2402 PLX3002Output Power (per channel):Continuous Average Output Power bo

PLX 3002 PCB ASSEMBLY (230V) Cont’d PLX 3002 PCB ASSEMBLY (230V) Cont’dPart NumberDescriptionReferenceCl.50CA-722001 -10CAP LYTIC RL 220UF 20% 1 OV NC

PLX 3002 PC6 ASSEMBLY (230V) Cont’dPLX 3002 PCB ASSEMBLY (230V) Cont’dPart Number Description Reference Part Number DescriptionReferenceQ39,73,79,Qal

PLX 3002 PCB ASSEMBLY (230V) Cont’dPLX 3002 PCB ASSEMBLY (230V) Cont’dPart Number Description ReferencePart Number DescriptionReferenceRE-175002-30 RE

PLX 3002 CHASSIS ASSEMBLY (230V)Part Number Description ReferenceCH-000097-00 CHASSIS, PLXCH-000100-00 HANDLE-EAR CASTING PLXCH-000112-00 SHIELD, AC,

0, ’lRFZ4lG-643AZ!?G D SOP-AMPNE5532ANDual Operational AmplifierPLX SeriesSemiconductor IdentificationTMOS FETlRFZ44TMOS Power Field Effect Transistor

PLX SeriesSemiconductor IdentificationTIMERDual TimerLM556CMPWM SwitchPWM MOSFET Gate DriverTOP21 0OP-AMPLMI 3600OP-AMPMC33078Dual Transconductance Op

PLX SeriesSemiconductor IdentificationIGBTlRG4PC5OUPLX2402, PLX3002insulated Gate Bipolar TransistorPWMSG3525ANRegulating Pulse Width ModulatorCOMPARA

SCREW, #8 X 5/16’L 73 REQD,.“..ce,c --- cCREW, #6-32 X 3/6* L., SEMSRECQHANDLE-EAR2 REDOKNOB J2 REWFACEPLATE LABELCHASSIS ASSEMBLYMEW A-Al HEX NUT (NW

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IntroductionThis manual is prepared to assist service personnel with the repair and calibration of PLX poweramplifiers . The procedures described in t

PLX MAIN MOOULE ASSEMBLYsmm, +6-20 Y 5/r I_1.w ’

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Test & CalibrationPLX 1202 Test Procedure. SET-UP1. Connect a test load to the output terminals of the amplifier.2. Make sure Mode Switches 1 - 10

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5. Turn power off and place the amplifier back into the Stereo mode with outputloads connected to each channel.. BIAS1. Let the amplifier cool down to

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4. Verify that the NTC circuit causes thermal shutdown after an extended period.5. When thermal shutdown occurs, verify AC idle current of less that 0