Motorola PM1200, Basic Service Manual

Page: 106 / 138

October 26, 2007 6880309U09-A
7-2 Basic Troubleshooting : Replacement Board Procedures
7.3 Replacement Board Procedures
Once a problem has been isolated to a specific board, use one of the following recommended repair
procedures:
• Install a good board from your inventory into the radio.
• Order a replacement board from Radio Products Services Division. Refer to
“Appendix A
Replacement Parts Ordering” on page A-1 for further information.
7.4 Transmitter Troubleshooting
Table 7-1 can help troubleshoot problems that might occur in the transmitter section of the radio.
Table 7-1. Transmitter Troubleshooting Chart
Symptom Possible Cause
Correction or Test (Measurements Taken at
Room Temperature)
No RF Power
Output Microphone Is the PTT switch being pressed correctly?
If yes, there is a possibility that there is no contact
inside the microphone.
Power current capacity Check whether there is a drop in supplied voltage.
Distorted
Modulation Frequency Setting Check to ensure the correct channel/ frequency is
selected.
No Modulation,
Bad
Microphone
Sensitivity Microphone Speak loudly into the microphone while monitoring
the microphone line (pin 5 of J3402 in dash
configuration).
If the voltage of pin 5 of J3402 is not greater than
80 mVrms, then check the microphone.
No/Low
Signaling (PL,
DPL, Trunking,
MDC) Check Programming Reprogram the codeplug using CPS.