Ericsson LBI-38701 Maintenance Manual
Ericsson LBI-38701 Maintenance Manual

Ericsson LBI-38701 Maintenance Manual

Service section 800 mhz trunked mobile radio

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800 MHZ TRUNKED MOBILE RADIO
Description ............................................................................................................................................
Initial Adjustment .................................................................................................................................
Transmitter Adjustment ................................................................................................................
Receiver Adjustment .....................................................................................................................
Re-installation................................................................................................................................
Preventative Maintenance ....................................................................................................................
Connections ...................................................................................................................................
Electrical System...........................................................................................................................
Mechanical Inspection ..................................................................................................................
Antenna ..........................................................................................................................................
Alignment.......................................................................................................................................
Frequency Check ...........................................................................................................................
Disassembly Procedures.......................................................................................................................
To Remove Top Cover..................................................................................................................
To Remove Bottom Cover............................................................................................................
To Remove The Duplexer Assembly...........................................................................................
To Remove The RF Board............................................................................................................
To Remove The Audio Board ......................................................................................................
To Remove The Front Cap Assembly .........................................................................................
To Remove The Logic Board .......................................................................................................
To Remove The Duplexer/Interface Board .................................................................................
To Remove The System Board ....................................................................................................
To Remove The Handset Interface Board...................................................................................
Chip Component Replacement ............................................................................................................
To Remove Chip Components .....................................................................................................
To Replace Chip Components......................................................................................................
Troubleshooting Procedures ................................................................................................................
Self Diagnostics/Error Messages .................................................................................................
Test Preparation ....................................................................................................................................
Test Mode Commands..........................................................................................................................
Default Conditions ........................................................................................................................
Channel Frequency Select ............................................................................................................
Test Mode Commands and Functions.................................................................................................
Single Key Tests............................................................................................................................
Three Key Function Tests.............................................................................................................
MAINTENANCE MANUAL
SERVICE SECTION

TABLE OF CONTENTS

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Summary of Contents for Ericsson LBI-38701

  • Page 1: Table Of Contents

    LBI-38701 MAINTENANCE MANUAL SERVICE SECTION 800 MHZ TRUNKED MOBILE RADIO TABLE OF CONTENTS Page Description ............................Initial Adjustment ..........................Transmitter Adjustment ........................ Receiver Adjustment ........................Re-installation..........................Preventative Maintenance ........................Connections ........................... Electrical System........................... Mechanical Inspection ........................Antenna ............................Alignment............................Frequency Check ...........................
  • Page 2 Radio Alignment Procedure ......................... Test Equipment And Service Aids ....................Transmitter Alignment ........................Receiver Alignment........................Transmitter Verification........................ Receiver Verification ........................Diagrams Audio Signal Flow Diagram ......................Control Signal Flow Diagram....................... Power Distribution Diagram......................© Copyright March 1992, Ericsson GE Mobile Communications, Inc.
  • Page 3: Description

    LBI-38701 DESCRIPTION ELECTRICAL SYSTEM Check the voltage regulator and alternator or gener- The Service Section contains the information neces- ator periodically to keep the electrical system within safe sary for aligning and troubleshooting the MDR Series and economical operating limits. Overvoltage is indicated mobile radio.
  • Page 4: To Remove Top Cover

    LBI-38701 duplexer and disconnecting the TNC connector from the TO REMOVE THE TOP COVER ANT port of the duplexer. Insert a small standard screwdriver under one side of the NOTE top cover and gently pry the side of the cover away from the frame releasing the locking tab.
  • Page 5: To Remove The Audio Board

    LBI-38701 Figure 2 - Bottom View With Duplexer 6. Remove the six M3.5-0.6 x 8 TORX screws (#15 drive) 2. Remove the two M3.5-06 x 8 TORX screws (#15 drive) from the bottom side of the board. from both sides of the front cap and the TORX screw on the bottom of the front cap.
  • Page 6 LBI-38701 Figure 3 - Bottom View Without Duplexer Figure 4 - Top View...
  • Page 7: To Remove The Duplexer/Interface Board

    LBI-38701 where the component is used (PA module replacement is TO REMOVE THE DUPLEXER located in the RF Board manual). INTERFACE BOARD A4 Replacement of chip capacitors should always be done Remove the top cover of the radio. Refer to the procedure with a temperature controlled soldering iron, operating at above.
  • Page 8: Troubleshooting Procedures

    LBI-38701 - Contains the main radio micro- 3. Place the "tinned" soldering iron on the other end of the component and the pad simultaneously. Apply solder to processor the top of the end of the component until the solder starts - Accepts PTT from the micro- to flow.
  • Page 9 LBI-38701 SYMPTOMS AND CHECKS SYMPTOMS CHECKS Handset Blank On Check for filtered A+ to the handset on J701. If absent, refer to the power distribution Power Up block diagram. Radio Will Not Go Into The radio must be PC programmed to enable the test mode. Enable it on the options Test Mode Operation screen.
  • Page 10 LBI-38701 SYPTOMS AND CHECKS (CONTINUED) SYMPTOMS CHECKS Radio Will Not Program Radio must be turned "on" before programming. Connect the handset and press the on/off When Plugged Into The power switch. TG3310 Interface Module Distorted Tx Audio Check grounding between all Boards and the casting.
  • Page 11: Test Preparation

    LBI-38701 TEST PREPARATION Channel Frequency Select To select a channel other than the frequencies in the To test the MDR radio, a test mode must be entered to current trunked set, press CLR followed by a 2 to 4 digit disable the normal channel scanning mode for GE-MARC channel number (10-1208) followed by "CLR".
  • Page 12: Single Key Tests

    LBI-38701 = Reset to default conditions the frequency set, sets the bandswitch line to the normal band, and displays [FSxx #01]. = Invoke a new function Mode (STO) = Exit test mode VOLUP = Ramp volume up STO returns the radio to the power-up state. I.e. [...
  • Page 13 LBI-38701 respectively. Tone 42 is the dial tone detect/all channels Decrement Frequency (4) busy tone. Tones 1 through 39 are transmitted at a high deviation level, while tones 40 through 42 are generated at The (4) command decrements the radio to the previous a low deviation level.
  • Page 14: Three Key Function Tests

    LBI-38701 Decrement Tone (6) Receive Audio Off (FCN 0 3) The (6) command decrements the tone number to the The FCN 0 3 function displays [ RXAUDOF] and previous GEMARC tone. If tone zero is displayed then the turns the receive audio off regardless of the carrier or tone tone wraps around to 42.
  • Page 15 LBI-38701 Each DTMF tone sequence consists of a LOW tone Manual Channel Increment (FCN 0 9) and a HIGH tone. The FCN 0 9 function increments the channel number Decode Test (FCN 1 3) and loads the synthesizer. The radio will then display the number of the channel loaded i.e.
  • Page 16 LBI-38701 Personality Prom Check (FCN 1 7) Band Switch (Direct Mode) (FCN 2 1) The FCN 1 7 test displays [PROMTEST] for one The FCN 2 1 test displays [ BSWCH-0] then pulls the second an then displays a 30 second display count of when bandswitch line of the VCO low.
  • Page 17: Radio Alignment Procedure

    LBI-38701 isting cable is not looped through Tone Channel Guard Encode (FCN 2 5) the front of the radio assembly • 19A801348P4 The FCN 2 5 function checks the lock detect line of Provides a two foot extension be- the synthesizer and displays [ UNLOCK ] if the synthesizer tween the 9-pin "D"...
  • Page 18: Receiver Alignment

    LBI-38701 Figure 5 - Tuning and Adjustment Control Location Direct Mode Modulation Set (for radios Transmitter Power Set with the talk-around option installed) 1. While on channel 649, key the transmitter (FCN 0 1), and adjust R111 in the power control circuit for 11 watts.
  • Page 19: Transmitter Verification

    LBI-38701 1. Inject a strong on channel signal modulated by 1 kHz IF Tuning tone at 3 kHz deviation at the RF input. 1. Monitor J501 with an AC voltmeter and inject an on 2. Turn the RX audio on (FCN 0 2) and set the volume at channel signal at the antenna jack modulated with a 60Hz maximum.
  • Page 20: Receiver Verification

    LBI-38701 4. Select channel 649 (CLR 6 4 9 CLR) at 814.0000 MHz. Audio Output Turn on the TX audio (FCN 0 4). Turn on the busy tone (FCN 2 5) which also keys the transmitter. 1. Apply a strong (-60 dBm) on channel signal modulated 5.
  • Page 21: Audio Signal Flow Diagram

    AUDIO SIGNAL FLOW DIAGRAM LBI-38701 Figure 6 - Audio Signal Flow Diagram...
  • Page 22: Control Signal Flow Diagram

    LBI-38701 CONTROL SIGNAL FLOW DIAGRAM Figure 7 - Control Signal Flow Diagram...
  • Page 23: Power Distribution Diagram

    POWER DISTRIBUTION DIAGRAM LBI-38701 Figure 8 - Power Distribution Diagram...

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