Technical Manual

GUARDIAN VHF 110W MOBILE 6-1
CHAPTER 6: SERVICING THE RADIO
6.1 General
There are no user serviceable parts in the Guardian radio. Return it for servicing to the manufacturer after
requesting an RMA number. Attempts to service the Guardian radio by non-authorized personnel voids the
warranty.
6.2 Self-Test at Power Up
At radio switch-on, the H8 controller executes a number of tests to confirm correct operation. Any errors are
reported to the user through displayed error messages and logged in the Flash. The tests implemented include:
• Flash checksum CRC
• RAM read and write
• FPGA configuration
• DSP host interface
• Keypad interface to AVR
• DC bus interface
• Transceiver EEPROM interface
• Synthesizer lock tests top and bottom frequencies, lock time, etc.
6.3 Caution
Repair of some parts of this unit require special tools and soldering techniques not normally available in a field
service environment. DWC highly recommends the module subassemblies be returned to the factory for service.
Damage can easily occur from repair attempts by non-trained personnel.