Mackie SRM550 - Appendix A: Service Information; Troubleshooting

SRM550 • SRM650 • SRM750 Powered Loudspeakers
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SRM550 • SRM650 • SRM750 Powered Loudspeakers
Appendix A: Service Information
Poor bass performance
• Checkthepolarityoftheconnectionsbetweenthe
  mixerandtheloudspeakers.Youmayhaveyour
  positiveandnegativeconnectionsreversedatone
  endofonecable,causingoneloudspeakertobe
  out-of-phasewiththeother.
• Poorbassperformancemaybetheresultofbad
  ACpower.Seethesectiontitled‘ACPower’on
  page13forfurtherdetails.
Poor sound
• Isitloudanddistorted?Makesurethatyou’renot
  overdrivingastageinthesignalchain.Verifythat
  alllevelcontrolsaresetproperly.
• Istheinputconnectorpluggedcompletelyinto
  thejack?Besureallconnectionsaresecure.
Noise
• Whatisthepositionofthegainknob?Itshould
  beat(ornear)“mic”whenamicisconnected
  andat(ornear)“line”whenaline-levelsignal
  isconnected.Itshouldbe“off”forallunused
  inputs.
• Makesureallconnectionstotheactive 
  loudspeakersaregoodandsound.
• Makesurenoneofthesignalcablesarerouted
  nearACcables,powertransformers,orother
  EMI-inducingdevices.
• IstherealightdimmerorotherSCR-baseddevice
  onthesameACcircuitastheSRMloudspeaker?
  UseanAClinelterorplugtheloudspeakerinto
  adifferentACcircuit.
IfyouthinktheSRMloudspeakerhasaproblem,
pleasecheckoutthefollowingtroubleshootingtipsand
doyourbesttoconrmtheproblem.VisittheSupport
sectionofourwebsite(www.720trees.com)whereyou
willndlotsofusefulinformationsuchasFAQsand
otherdocumentation.Youmayndtheanswertothe
problemwithouthavingtopartwithyourloudspeaker.
Troubleshooting
No power
• Ourfavoritequestion:Isitpluggedin?Makesure
  theACoutletislive[checkwithatesterorlamp].
• Ournextfavoritequestion:Isthepowerswitch
  on?Ifnot,tryturningiton.
• IstheRunningManlogoonthefrontpanel 
  illuminated?Ifnot,makesuretheACoutlet
  islive.Ifso,referto“Nosound”below.
• TheinternalAClinefusemaybeblown.Thisis
  notauserserviceablepart.Ifyoususpectthe
  AClinefuseisblown,pleaseseethe"Repair"
  sectionnext.
No sound
• Istheinputgainknobfortheinputsource 
  turnedallthewaydown?Verifythatallthegain
  knobsinthesystemareproperlyadjusted.Look
  atthelevelmetertoensurethatthemixeris
  receivingasignal.
• Isthesignalsourceworking?Makesurethe 
  connectingcablesareingoodrepairandsecurely
  connectedatbothends.Makesuretheoutput
  levelcontrolonthemixingconsoleisturnedup
  sufcientlytodrivetheinputsofthespeaker.
• Makesurethemixerdoesnothaveamuteonora
  processorloopengaged.Ifyoundsomethinglike
  this,makesurethelevelisturneddownbefore
  disengagingtheoffendingswitch.
• Hasitshutdown?Makesurethereisatleast
  sixinchesoffreespacebehindeachSRM 
  loudspeaker.