Diagnose Three Fictional AV Field Failures
Learning objectives
- Diagnose three faults from symptoms and measurements.
- Write a step-by-step test sequence for each.
- Identify the root cause and the fix.
Lab brief & instructions
Three field failures arrive as tickets. For each, list the symptom, the measurements you would take, the test sequence, the root cause, and the fix.
Fault 1 — No video on the right display
Symptom: laptop shows on the left display but not the right. Source is outputting; switcher status shows the route to both outputs. Suspect the display input selection or the run to the right display.
Fault 2 — Far end hears echo
Symptom: the remote participants hear themselves a moment after they speak. Local audio sounds fine. Suspect AEC not enabled, wrong reference, or room speakers too loud.
Fault 3 — Touchpanel will not connect after a network change
Symptom: panel shows 'connecting' indefinitely; control processor is fine. Recent network reconfiguration. Suspect wrong VLAN, moved port, or lost DHCP reservation.
Write each diagnosis as a one-page case: symptom, measurements, test sequence, root cause, fix. The reasoning is the deliverable; no hardware needed.
Implementation checklist
- ✓Each fault has symptom, measurements, test sequence, root cause, fix.
- ✓Test sequences are step-by-step and single-change.
- ✓Root cause, not just symptom, identified.
Downloadable study guide
01. Fault 1: trace video path; suspect display input or the right-display run. 02. Fault 2: AEC enable/reference/room level; verify per mic. 03. Fault 3: VLAN/port/DHCP reservation after a network change. 04. Document each as symptom → measurements → test sequence → cause → fix.