Motorola ASTRO XTL 5000 Basic Service Manual page 127

Basic Troubleshooting: Receiver Troubleshooting
Symptom
Radio Will Not
Squelch
Radio Will Not
Turn Off
Excessive
Noise in Fading
Conditions
Radio
transmiits when
programming
cable is
inserted into
control head
6881096C73-O
Table 9-6. Receiver Troubleshooting Chart (Continued)
Possible Cause
Codeplug
On/Off Switch (Control
Head)
Emergency Switch
Main Board
Check Programming for
Correct Bandwidth
Damaged Flex
Correction or Test (Measurements Taken
at Room Temperature)
Check the offending channel for spurious activity
by monitoring with a known-good radio or service
monitor.
If possible, remove the offending source (computer,
etc.).
If not, increase the squelch level using the
appropriate radio-programming software.
Check for SW_B+ at 0 Vdc on pin 17 J0401 on the
main board.
If SW_B+ is >1 Vdc, replace the control head.
Check the emergency signal at J0401-18. A high
voltage may indicate that the emergency switch
line is not grounded by the rear accessory cable.
Refer to the Detailed Service Manual.
Reprogram the codeplug with the correct
bandwidth.
Replace flex to control head.
9-9
June 11, 2003