Adcom GFP-815 manual Troubleshooting

Page 7

 

SYMPTOM

POSSIBLE REASON

POSSIBLE SOLUTION

PowerLEDdoesnot glow.Nosound

PowerLEDglows,butno sound

Onechannelnotproduc ingsound

Humfromallspeakers atanyvolume

Humfromallspeakers (humgoesupordown withvolume)

Humfromtheamplifier itself

ACPowerCord(s)notpluggedin.AC

Fuse(s)failed.Transformerthermalprotec

tionengaged.I2VDCtriggeringmalfunc

tioning.

Preamporsourceunitisnoton.Connec

tionsinrearofampareloose.

INPUT(s)orOUTPUT(s)connectordiscon

nectedorloose.Speakerdisconnected.

Internalprotectionengaged.

Groundloop(differenceingroundvoltages betweencomponents).

Problemwithsourceunit(CD,tape,etc.), orRCAcableconnectingthatsourceunitto thepreamp.

Somemajorappliance,dimmer,halogenor

fluorescentlightiscreatinginterference.

PluginACPowerCord(s).ReplaceAC Fuse(s).Waituntilunitcoolsdown.Itwill reset.Resetpowerswitchmanually. Checkconnectionof12VDCtriggerat source.

Makesurewholesystemison.Verifyall

connectionsonrearofamp.

Verifybothconnectionsonthatchannel.

Verifyconnectionatspeaker.Bringto

DealerorServiceCenter.

IfCableTVispresent(seeNote1).IfCa bleTVisnotpresent(seeNote2).

Trydifferentsource(tuner,tape,etc.)

and/ordifferentRCAcable.

Makesureallappliances,dimmersand

suspectlightsareoff.

Troubleshooting

Usethetroubleshootingnotesabovetosolvecommon sit

uationsthatdon’trequireprofessionalattention.If the

stepsstatedinpossiblesolutiondonotresolveyour prob

lem,thenpleasecontactyourADCOMdealerorcall the ADCOMcustomerservicedepartment.Anyproblemsnot

coveredhereshouldbebroughttotheattentionof your ADCOMdealerorADCOMcustomerservicedepartment.

A special note on “hum:”Whenthereisalowvolume “hum”audiblethroughoutyourspeakers,evenwiththe

mainvolumeturnedallthewaydown,youhaveacom mon

phenomenonknownasa“groundloop.”Agroundloop is

basicallyadifferenceingroundvoltagesbetweentw oor morecomponentswhichareconnectedelectricallyand whichcreatesmultiplecurrentpathswheretheremust

onlybeone.Thisdifferenceinpotentialscreatesa6 0Hz

lowlevelsound(approximatelyalowA),thatseems tobe a“hum.”

Humcanbecausedbyaddingnewcomponentstoyour

system,butthatdoesnotimplythereisanythingelect ri

callywrongwithanynewcomponent.Withtheadvent of audio/videoandhometheatersystems,theproblemhas

becomecommonplace.Generally,thecauseistheCab le

TVincomingsignalline.Thisnewincominglinemay add

anadditionalgroundatadifferentpotentialtoth eAC

linegroundofyourotherequipment(refertonote Iand 2,totroubleshootahumproblem).

Note 1:CableTVsystemscansometimescontributeto

 

groundloopproblemswhichcause“hum.”Todetermine

if

your cablesystemisthecontributingfactor,disconnectt

he

CableTVincomingsignalline(round,75)atthewa ll,

orthefirstcomponentthecableisconnectedto(i. e.the

cablebox,orVCR).Ifthehumisnolongerpresent, you mustinserta“75groundloopisolator”beforerecon

nectingtheline.YoushouldcheckwithyourADCOMd eal

ertoobtainone.Ifthe“75groundloopisolator” works

onlypartiallyornotatall,thenpleasereadnote 2to completethetroubleshootingprocedure.

Note 2:Makesurethatthepoweramplifierisatleast6” fromprocessororotherequipmentusingmicroprocessor s.

Usuallyputtinganothercomponentbetweenthemissu f

ficienttominimizethehum.Ifthisdoesnotreduce the

hum,turnthesystemoffanddisconnectallInputsfr om

theamplifier.Ifthehumstillpersists,thenyourdea leror

servicecentermustexaminetheunit/system.Ifthehu m disappears,tryanothersetofRCAcables.Connectone

RCAcableatatimetoseeifonespecificcableis respon

sible.Ifanyorallcablescausethehumtoappear, then

theunitshouldbeevaluatedforproperoperationby your dealerorauthorizedservicecenter.P leaseseeourwebsite

foralistofauthorizedservicecentersinyourarea .

Servicing

ADCOMhasatechnicalservicedepartmenttoanswer

 

questionspertinenttotheinstallationandoperatio

nof

yourunit.Intheeventofdifficulty,pleasecontac

tusfor

advice.Ifyourproblemcannotberesolvedthrougho

ur

combinedefforts,wemayreferyoutoanauthorized

re

pairagency,orauthorizereturnoftheunittoour

facto ry.

Image 7
Contents Page About Adcom Anyoutdoorantennamustbelocatedawayfrom allpowerlines Unpacking the GFP-815 Key FeaturesSafety Information IntroductionBalance Knob Headphones JackStandby button Source Selections Bass & Treble KnobsRemote Control Volume Knob Ext RemoteVoltage switch Bottom Main power switchTroubleshooting Warranty USA & Canada GFP-815 Specifications Introduction Email info@adcomusa.com