54
TM8000 Encryption
Midian Encryption Programming and Service Manual
June 2006 © Tait Electronics Limited
4.6
TM8000 Fault Finding
Symptom
Cause
Action
Radio transmits regularly -goes
into emergency mode
Audio not operating
Radio stopped working after it
was dropped.
Module not squarely in connector
Re-plug connector to
module (radio will need to
be opened)
Receives okay, but no transmit
audio.
Module may not be receiving PTT
Check PTT links.
Encryption on/off button only
changes encryption state every
second press
Module may be programmed for level-sensitive
instead of edge-sensitive.
Reprogram encryption
module.
Module does not decrypt audio.
Module may have been programmed differently
to the rest of the fleet.
Reprogram with correct
settings.
Radio will not power up properly,
shows database error, continuous
Red LED.
Radio has been downloaded with incorrect
firmware and/or programmed with incompatible
software.
Contact Customer support.
Radio will not power up properly,
display blank.
Flex-edge connectors may not be correctly
plugged.
Module faulty.
Replug connectors checking
flex is square to connector.
Replace module.
Radio set to one code can hear
another radio no matter what
code it is set to.
Module may have same code strings set in all
code registers.
On TOP radio, flex IC1 may not be working, or
not getting address information from micro.
Reprogram module with
different codes.
Replug loom connectors,
check circuit.
Audio sounds very muffled
Inversion module may have very low inversion
frequency.
Program module to a higher
frequency.
Audio sounds very “thin”.
Inversion module may have very high inversion
frequency.
Program module to a lower
frequency.
Audio sounds unusually high
pitched or low pitched.
Transmit and receive inversion frequencies may
be different.
Ensure both radios are using
same frequency. If problem
still exists, reprogram
module
Receiving radio occasionally or
frequently fails to decode sync
pulse. Audio is unintelligible for
several seconds then comes right.
System delay may be set too short
Reprogram module, or
consider if CTCSS can be
removed from some parts of
radio system.
Radio confidence and alert tones
are different, rapidly varying
tones.
This is normal when either the transmitting or
receiving radio creates an alert tone or
confidence tone during an encrypted
conversation.
No action - not a fault
Radio makes unusual, distorted
beeps at turn on.
Radio confidence tones may be set to high. (Not
all radios exhibit this)
Reprogram radio to set
confidence tones to low.
