User's Manual

sales representative for details about this mode. All other combinations of the dipswitch
are not supported and will default to the Normal mode.
7. Maintenance and Troubleshooting
The following paragraphs contain information to help you maintain and troubleshoot the
VRS. A list of recommended test equipment is found in the "Recommended Test
Equipment, Service Aids, and Tools" section of the ASTRO Spectra Basic Service
Manual, Motorola publication 68P81076C20.
Additional information may be found in the Troubleshooting Chart in this manual.
Troubleshooting Procedures
VRS Activation
1. Turn on the mobile radio control head. The radio should go through self-check
and then display the home mode of the mobile radio.
2. Possible error messages on power up are:
o ERR 12/10 - No VRS detected. See "Common Power Up Problems" section on
page 38 for possible solutions.
o ERR 12/81 - Flash EPROM failure. If re-flashing the unit does not fix this
problem the HT750 transceiver should be replaced.
o ERR 12/82 - Codeplug checksum error. After verifying that both mobile and VRS
have the correct software version, checking the mobile-to-VRS connection, and moving
the cable away from any interference, reprogram the VRS750's codeplug using the
correct version of the CPS. If the codeplug cannot be corrected using CPS then the unit
will need to have a new default codeplug written to the unit.
o ERR 12/84 - CONFIG register corruption. The unit should be flashed with the
correct version software. If this fails to correct the problem, the HT750 transceiver should
be replaced.
o ERR 12/88 - HC11 RAM failure. Replace the HT750 Transceiver.
o VRS 001 - VRS Synthesizer out of lock error. See "Common Power Up
Problems" section on page 38 for possible solutions. If the solutions in the “Common
Power Up Problems” section do not fix the error then the HT750 transceiver should be
replaced.
o PROG VRS - The VRS750 is in programming configuration. This is only an
error if the programming cable is not plugged into the front connector of the VRS750.
Reset the ASTRO Mobile radio and if the problem is not corrected check P101 Pin 9 and
the PROG_SENSE line for any shorts to ground.
3. Enable the VRS unit by pressing the VRS button on the mobile control head.
o "VRS BOTH" must be displayed momentarily on the control head and the
indicator must light.
o Verify a short single tone burst is transmitted upon activation at approximately 3
KHz deviation for a channel spacing of 25 kHz. NOTE: Because of the short burst, it may
be necessary to verify the deviation on the modulation scope instead of the usual
deviation meter. Activation may be repeated by pressing the VRS button once to disable
the unit and again to reactivate it.