Harris DX 25U - Page 85

ColorStat™ panelPredriverFault .............................................................. 6-13
ColorStat™ panelRFAmpFault............................................................... 6-13
ColorStat™ panel Analog Input Board: +15V and -15V Supply Faults . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-13
ColorStat™ panel Analog to Digital Converter. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-13
+15V, -15V, and +5V Supply Faults . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-13
Conversion Error Fault . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-13
ColorStat™ panel Modulation Encoder: Cable Interlock Fault . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-13
PossibleCauses......................................................................... 6-14
RF Amplifier Module Not In Place. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-14
Modulation Encoder Cable Not In Place. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-14
ColorStat™ panelDCRegulatorB+andB-SupplyFaults.......................................... 6-14
ColorStat™ panelOutputMonitorFaults........................................................ 6-14
+5Vand-5VSupplyFaults ............................................................... 6-14
VSWRFaults........................................................................... 6-14
GeneralDiscussionOfVSWRProtectionoftheTransmitter................................. 6-14
First Stage VSWR Protection 6-15
Second Stage VSWR Protection 6-15
AntennaVSWRFault................................................................. 6-15
Possible Causes of VSWR Overloads 6-15
Possible Causes of Arcing 6-15
Possible Causes of Transient Signals 6-15
Load Impedance Changes 6-15
Bandpass Filter VSWR Fault. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-16
Bandpass Filter VSWR Caused By Problems In The Output Network 6-16
Symptom:LossOfPositivePeakCapability...................................................... 6-16
PossibleCauses......................................................................... 6-16
PowerSupplyVoltageLow............................................................ 6-16
AudioProcessorEquipmentDefectiveorIncorrectlySet.................................... 6-16
IncorrectTransmitterTuning........................................................... 6-16
Transmitter Operated In FlexPatch™ Mode............................................... 6-16
FailedRFAmplifier.................................................................. 6-16
Symptom:HigherThanNormalAudioDistortion................................................. 6-16
PossibleCauses......................................................................... 6-16
FailedRFAmplifier(s)................................................................ 6-16
TransmitterMistuning................................................................ 6-16
OperatingIntoaBandwidthRestrictedAntenna ........................................... 6-16
Low RF Drive Level To The PA Modules . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-16
AdditionalTipsForTroubleshootingAudioTHD.......................................... 6-16
Symptom:ConsistentLossofRFAmplifiers..................................................... 6-17
RepeatedLossofSameRFAmplifierInAnyPosition.......................................... 6-17
PossibleCauses ..................................................................... 6-17
Defective Transistor Pad 6-17
Defective Turn On/Turn Off Circuitry 6-17
Improper RF Drive 6-17
Poor Solder Connection on PC Board 6-17
ConsistentLossOfAnRFAmplifierInOneParticularPosition.................................. 6-17
PossibleCauses ..................................................................... 6-17
Improper RF Drive 6-17
Improper Drain Phasing 6-17
Defective Output Toroid 6-17
Improper Control Signal 6-17
Consistent Loss Of Modules In Random Positions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-17
PossibleCauses ..................................................................... 6-17
Analog to Digital Phasing Improperly Set 6-17
Modulated B- Improperly Set 6-17
Improper VSWR Circuit Operation 6-17
Section VI - Troubleshooting
Rev. R: 11-11-96 888-2297-002 6-3
WARNING: Disconnect primary power prior to servicing.