Service manual

Page 5
Symptom PossibleCauses Fix
5vSupplyreadslow,
frontpanelseems
lockedup
C24onDCDboard MakesureC24is
mountedtherightdi‐
rection,resolderit.
DCDTraygetsveryhot Normalwithoutcover
on
Attachtopcover.The
extraheatsinkingand
fanswillkeepthe
traycool
AntennaA/Brelays
don’tswitch
Unsolderedpins RemoveDCDboardand
checksolderconnec‐
tionsonallrelays
Transmitterdoesnot
transmit
TXPVCCsignalinopera‐
tive
Makesurethereisno
voltageontheTxIn‐
hibitinputonthe
Linearinterfacecon‐
nector.CheckQ13base
(shouldread9.1V).
CheckR68,D18,R4,
R5,Q16.Makesure
LPTTgoeslowduring
transmit(gateof
Q16).Checkcontinuity
throughlowpassfil‐
ters.MakesureQ4and
Q5jumpersagreewith
installedtransistor
types.
IFFilterBoardfails
test
Solderconnections.
ICsmountedbackwards.
Cableattachedto
wrongsideofboard.
Jumpersontestboard
setwrong.
Inspectallsolder
joints.Makesurepin
1ofICsisinsquare
pad.Makesure8‐pin
cableisattachedto
bottomsideofboard.
Re‐checkthejumpers
onthetestboard.
RxBPFfailstest Toroids,soldering,
filtersnotinstalled,
powerconnectorsin‐
stalledonwrongside
ofboard
Measurecontinuity
acrosstoroids,resol‐
der.Re‐heatallsol‐
derconnections.Make
sureconnectorsare
mountedright.