x Table of Contents
May 25, 2005 6881096C74-B
4.8.3 Out-of-Lock Condition .....................................................................................................4-22
4.8.4 No or Low Output Power (TX or RX Injection) ................................................................4-22
4.8.5 No or Low Modulation .....................................................................................................4-22
4.8.6 Troubleshooting the Back-End ........................................................................................4-22
4.9 700–800 MHz Main Board Troubleshooting.................................................................................4-22
4.9.1 Display Flashes “FAIL 001” .............................................................................................4-23
4.9.2 FGU Troubleshooting Aids ..............................................................................................4-24
4.9.3 No or Low Output Power (TX or RX Injection) ................................................................4-28
4.9.4 No or Low Modulation .....................................................................................................4-28
4.9.5 Troubleshooting the Back-End ........................................................................................4-28
4.10 Standard Bias Tables ...................................................................................................................4-28
4.11 Receiver Front-End (RXFE) .........................................................................................................4-33
4.11.1 VHF (136–174 MHz) Band ..............................................................................................4-33
4.11.2 UHF Range 1 (380–470 MHz) Band ...............................................................................4-33
4.11.3 UHF Range 2 (450–520 MHz) Band ...............................................................................4-34
4.11.4 700–800 MHz Band.........................................................................................................4-34
4.12 Power Amplifier Procedures.........................................................................................................4-34
4.12.1 VHF (136–174 MHz) Band ..............................................................................................4-34
4.12.1.1 50-Watt Power Amplifiers.......................................................................................4-34
4.12.1.2 General Troubleshooting and Repair Notes...........................................................4-34
4.12.2 UHF Range 1 (380–470 MHz) Band ...............................................................................4-35
4.12.3 UHF Range 2 (450–520 MHz) Band ...............................................................................4-35
4.12.4 700–800 MHz Band.........................................................................................................4-35
Chapter 5 Troubleshooting Charts......................................................5-1
5.1 Introduction.....................................................................................................................................5-1
5.2 List of Troubleshooting Charts .......................................................................................................5-1
5.3 Troubleshooting Tables..................................................................................................................5-3
5.3.1 For Mid Power models ......................................................................................................5-3
5.3.2 For High Power models and UHF R2 Mid Power..............................................................5-7
5.4 Troubleshooting Test Points.........................................................................................................5-12
5.5 Board ID Jumper Configuration....................................................................................................5-13
5.6 Flowcharts ....................................................................................................................................5-14
5.6.1 Poor RX Sensitivity or No RX Audio (136–174 MHz)—Part 1 of 2..................................5-15
5.6.2 Poor RX Sensitivity or No RX Audio (136–174 MHz)—Part 2 of 2..................................5-16
5.6.3 RX IF—Poor SINAD or No Audio (136–174 MHz) ..........................................................5-17
5.6.4 RX Back-End—Poor SINAD or No Audio (136–174 MHz)—Part 1 of 3..........................5-18
5.6.5 RX Back-End—Poor SINAD or No Audio (136–174 MHz)—Part 2 of 3..........................5-19
5.6.6 RX Back-End—Poor SINAD or No Audio (136–174 MHz)—Part 3 of 3..........................5-20
5.6.7 Low or No RX Injection Signal (136–174 MHz)...............................................................5-21
5.6.8 Low or No TX Injection Signal (136–174 MHz) ...............................................................5-22
5.6.9 TX or RX VCO Unlock (Fail 001) (136–174 MHz)—Part 1 of 2.......................................5-23
5.6.10 TX or RX VCO Unlock (Fail 001) (136–174 MHz)—Part 2 of 2.......................................5-24
5.6.11 No Output Power at TX Mode (136–174 MHz) ...............................................................5-25
5.6.12 No Output Power and IDC < 2A at TX Mode (136–174 MHz).........................................5-26
5.6.13 No 16.8 MHz Reference Oscillator Frequency (380–470 MHz and 450–520 MHz)........5-27
5.6.14 Poor RX Sensitivity or No RX Audio (380–470 MHz and 450–520 MHz)—Part 1 of 2 ...5-28
5.6.15 Poor RX Sensitivity or No RX Audio (380–470 MHz and 450–520 MHz)—Part 2 of 2 ...5-29
5.6.16 RX IF—Poor SINAD or No Audio (380–470 MHz and 450–520 MHz)—Part 1 of 2........5-30
5.6.17 RX IF—Poor SINAD or No Audio (380–470 MHz and 450–520 MHz)—Part 2 of 2........5-31
5.6.18 RX Back-End—Poor SINAD or No Audio (380–470 MHz and 450–520 MHz)—
Part 1 of 3........................................................................................................................5-32