Fault Diagnostics

Symptom → check sequence, simple to complex

Completely dead

  1. Outlet/cable: another device in the same outlet
  2. Cord & plug: continuity for open wire
  3. Input fuse: continuity, replace ONLY same rating
  4. Power button/switch: contact continuity
  5. PSU: output voltage at connector under load
  6. PSU alive but board silent — hunt shorts on power rails

Always simple to complex: power → connections → components. Half of 'failures' are a cable, outlet or oxidized contact. Before poking — power off and discharge capacitors.