Maxon Telecom SM-2000 service manual Page-58 December

Page 62

MAXON SM-2000 MOBILE

TROUBLE SHOOTING CHART (SM-2000)

No TX

1.Defective MIC

2.Defective CPU IC409

3.Defective IC412

No TX Power

1.Defective TX enable Q122

2.Defective APC Control Circuit Q125

3.Defective TX Power Buffer AMP Q116 and Q117

4.Defective TX Power Amp (SM-2150) Q118,Q120

5.Defective TX Power Module (SM-2450) IC103

6.Defective ANT SW D108 and D120

7.Defective ANT Connector

Over Power

1.Programming

2.Q125 Short

3.Defective D107 and APC Circuit

Low TX Power Output

1.Wrong Programming

2.Defective TX AMP (SM-2150) Q116 , Q117 , Q118, Q120 and D108

3.Defective TX AMP (SM-2450) Q116 , Q117 , IC103 , and D108

4.Defective Antenna Connector

No Modulation

1.Defective MIC

2.Defective Analog SW IC412 and IC411

3.Defective 300Hz HPF IC410

4.Defective MIC AMP and Splatter Filter IC404

5.Defective Audio Buffer IC405

6.Wrong Alignment of RV402

7.Defective Analog IC401

No Encode of CTCSS/DCS

1.Wrong Programming

2.Defective CPU IC409

3.Defective IC407 and IC411

No Sensitivity

1.Defective Antenna Switch D108 , D120 , and D121

2.Defective Front-End Module

3.Defective DBM IC102

4.Defective 45MHz IF Filter CF101

5.Defective IF IC109

Wrong Frequency

1.Wrong Alignment of 12.8MHz TCXO

2.Wrong Programming

Page-58-

December 98

Image 62
Contents SM-2000 Page Table of Contents Maxon SM-2000 MobileSM-2000 Exploded View Schematics and Block DiagramsPCB Layouts General SpecificationsTransceiver Nominal Performance Transmitter Operational BandwidthBand Specfications Receiver TX Tone Modulation CharacteristicsSUB Audible Tones DCS Subaudible tones CTCSS/DCS RX Tone Demodulation CharacteristicsAccessories Reliability AnalysisIntroduction Unpacking Information Check the carton carefully for the following itemsGeneral Description Description of Controls Description of ControlsSM-2000 Rear Panel CTCSS/DCS Decode Circuits Theory of OperationDigital Circuitry CTCSS/DCS Encoder CircuitEeprom PLL RF Section SM-2150/VHF RX VCO TX VCOReceiver Out of Lock DetectorPrescaler RF AmplifierAudio Amplifier Receiver Audio CircuitLow Pass Filter Noise Detect Circuit SQ BoardFrequency Synthesizer Circuit RF Section SM-2450/UHFUHF Transmitter Second Oscillator- Mixer- Limiter and FM Detector Voltage Controlled Oscillator CircuitFirst Mixer Noise Detector Squelch Mute CircuitSquelch Noise Band Pass Filter Speaker Audio AmplifierTest Setup Transmit TestsSM-2150/VHF Alignment Procedure PLL AlignmentDiscriminator Tuning Receiver Alignment RFSquelch Adjustment Automatic Power AdjustmentCTCSS/DCS Deviation Adjustment Modulation Deviation AdjustmentAlignment Points Diagram SM-2150/VHF SM-2450/UHF Alignment Procedure Page-28 December ∙ Note Release the PTT button when changing channels Page-30 December Alignment Points Diagram SM-2450/UHF Surface Mount Removal Component ReplacementSurface Mount Components Surface Mount Component Replacement Surface Mounted Integrated Circuit ReplacementParts List Common to SM-2000 REF # DescriptionDigital Parts Common on Both VHF & UHF Digital Section Band Chart REF # Description FRONT-END PCB Assembly Main Board PartsPage-38 December Page-39 December Page-40 December Page-41 December SM-2450A UHF Band SM-2450C UHF Band SM-2450D UHF Band Band Chart SM-2450E UHF BandPage-44 December Page-45 December Page-46 December Page-47 December Component Pinout Page-49 December Page-50 December Voltage Charts SM-2150/VHF IC409Page-52 December Transistor Voltage Chart Voltage Charts SM-2450/UHF IC404 Page-56 December Trouble Shooting Chart SM-2000 Status Indications & Audible TonesPage-58 December Replacement Module Schematics MMBV109MA-4472 Microphone Schematic Page-61- December Page-62- December Page-63- December Page-64- December SW5 SM-2000 Control HeadSM-2150/VHF Main Board Assy Page-66 DecemberSM-2450/UHF Main Board Assy FrontSM-2000 SM-2150/VHF Exploded View Parts List Intentionally Left Blank