Troubleshooting a trunked system is pattern recognition: a cluster of symptoms points to a failed subsystem. Inject a fault, watch how the system and dispatch react, then commit to a diagnosis — and find out whether you reasoned it right.
Conceptual model built on public P25 behavior (failsoft, site trunking). Not Motorola core software — no real alarm codes or service procedures. Symptoms illustrate documented failure modes to train the reasoning, not memorization of any product's screens.
Failsoft — the trunking controller / control channel is lost, so the site can't trunk. Transmitters drop to conventional repeater mode; radios beep and fall to a preset failsoft frequency. Talkgroups, unit IDs, roaming, patch/multiselect — gone.
Site trunking (island site) — the site loses its network link to the core but its control channel stays up. Local users still trunk to each other, but they're cut off from other sites and often from dispatch.