Service manual

Guide to ASTRO™ Digital Radios
Figure 5.2 A photo illustration of a model number tag on the rear of a Motorola Inc. ASTRO Digital Spectra™. There are several useful pieces of
information displayed in the tag, including the model number, serial number, manufacture code (FLASHport™), host firmware flash ROM size
(1M) and indication of a 2.5 KHz narrow-band RF board.
The ASTRO Digital Spectra™ has been through many different revisions of command boards. The
command board is what interfaces the vocon to the control head, PA and RF boards. It is the nerve-
centre of the radio. If you’re buying a second-hand ASTRO Digital Spectra™, you’ll need to become
acquainted with the command board, as there are several modifications that must be performed to
ensure stable operation.
In 2003, Motorola Inc. discovered their new Universal Cryptography Module (UCM) had a timing
issue with the ASTRO Digital Spectra™. The fault caused the module to intermittently fail when key-
loading, receiving an over-the-air re-key communication (OTAR) or when the radio is first powered on.
When the failure occurs, “Fail 09/10” or “Fail 01/90” may display on the control head. This issue is
discussed in detail in SRN-1364.
The fix is simple, but not for the faint of heart. It involves complete disassembly of the radio and
removal of the command board and access to the RF board on the underside of the radio, under the
shield. A SMD rework station is required—or a steady hand and a <30W iron with a fine tip will suffice.
Figure 5.3 ASTRO Digital Spectra™ command board. Note areas 1, 2 and 3. These areas require special attention as per SRN1364.