Motorola Astro XTL 5000 Basic Service Manual

6881096C73-O June 11, 2003
Basic Troubleshooting: Replacement Board Procedures 9-5
9.1.4 Audio PA Out Bias
The audio PA is a BTL (bridge-to-load) amplifier. When the radio is in receiver mode, the output of
both speaker leads bias up to half of the supply voltage. Considering that both leads are at the same
potential, the average DC voltage across the load is zero. At maximum volume the signal voltage to
the load is double that of one amplifier peak-to-peak because the amplifiers work together 180
degrees out of phase. Caution must be taken not to short either lead to ground, which might cause
component damage. Even though audio may still be heard from the speaker, the shorted side will go
into current limiting and eventually into thermal shutdown, shutting off the amplifier. These protection
devices are not intended to be tested.
9.1.5 High Power RF Precaution
9.2 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 at 1-800-422-4210. Refer to
“Appendix A Replacement Parts Ordering” on page A-1 for further information.
• Troubleshoot the defective board using the ASTRO XTL 5000 Digital Mobile Radios Detailed
Service Manual. (Refer to the "Related Publications" section of this manual on page xii for the
specific manual number.)
9.3 Power-Up Error Codes
When the radio is turned on (power-up), the radio performs cursory tests to determine if its basic
electronics and software are in working order. Problems detected during these tests are presented
as error codes on the radio’s display. The presence of an error should prompt the user that a
problem exists and that a service technician should be contacted.
Self-test errors are classified as either fatal or non-fatal. Fatal errors inhibit user operation; non-fatal
errors do not. Use the following tables to aid in understanding particular power-up error code
displays.
When performing both transmit and, especially, receive tests, it is still
possible that equipment might be damaged by the radio transmitter.
Besides a possible radio failure, the radio might also transmit while in
receive under the fllowing conditions: trunking-mode affiliation, missing
emergency jumper, a defective PTT button, or other unintentional PTT
activations.
With the exception of some inputs on service monitors, a suitable attenuator
rated at 100 W or more should always be used with all test equipment
connected to the RF connector.
Table 9-3. Power-Up Error Codes
Error Code Description Error Type Corrective Action
ERROR 01/02 FLASH ROM Codeplug
Checksum
NON-FATAL Reprogram the codeplug.
ERROR 01/12 Security Partition
Checksum
NON-FATAL Reprogram the security partition.
!
C a u t i o n

Motorola Astro XTL 5000 Specifications

General

Brand	Motorola
Model	Astro XTL 5000
Category	Radio
Language	English