Motorola APX 4000 Basic Service Manual

9-4 Basic Troubleshooting: Transmitter Troubleshooting
9.4 Transmitter Troubleshooting
Table 9-4 lists the possible causes of, and corrections for, transmitter problems.
9.5 Encryption Troubleshooting
Table 9-5 lists the possible causes of, and corrections for, encryption problems.
Table 9-4. Transmitter Troubleshooting Chart
Symptom Possible Cause
Correction or Test (Measurements
Taken at Room Temperature)
No RF Power Out 1. TX Power Level or Frequency Check TX power level and frequency
programming (from tuner)
2. No Injection To Power
Amplifier
Send radio to depot
3. Antenna Switch/Connector
No Modulation;
Distorted Modulation
1. Programming Check deviation and compensation
settings using the tuner
2. Main Board Send radio to depot
Bad Microphone Sensitivity 1. Check Deviation and
Compensation
Realign if necessary
2. Microphone Send radio to depot
No/Low signaling
(PL, DPL, MDC)
1. Programming Check programming
2. Main Board Send radio to depot
Cannot Set Deviation
Balance
Main Board Send radio to depot
Table 9-5. Encryption Troubleshooting Chart
Symptom Possible Cause Corrective Action
No “KEYLOADING” on Radio Display When
Keyloading Cable is Attached to the Radio
Side Connector
1. Defective Keyload Cable Send radio to depot
2. Defective Radio
Keyloader Displays “FAIL” 1. Wrong Keyloader Type Use correct keyloader
type. Refer to Keyloader
User Guide for more
information
2. Bad Keyloader Try another keyloader
3. Defective Radio Send radio to depot

Motorola APX 4000 Specifications

General

IP Rating	IP67
Operating Temperature	-30°C to +60°C
GPS	Optional
Frequency Range	VHF: 136-174 MHz, UHF: 380-470 MHz, 450-520 MHz
Power Output	VHF: 1-5W; UHF: 1-4W
Digital Protocol	APCO P25
Dimensions	5.2 x 2.4 x 1.5 inches (without battery)