A home-care teenage patient reports the high-frequency chest wall vest runs but chest vibration feels weak, therapy takes longer to raise sputum, with new hissing at the hose connectors and a looser vest after weight loss. Which troubleshooting sequence should the therapist perform first to restore hyperinflation and secretion clearance?

Inspecting the hoses and garment fit, securing connections, and resizing the straps before retesting is the best sequence because the weak vibration, longer time to raise sputum, connector hissing, and looseness after weight loss point to both a circuit leak and poor chest coupling. Correcting both problems helps restore delivered pressure and transmission of oscillation needed for hyperinflation and secretion clearance. Cleaning the air inlet filter and verifying generator output pressure can address generalized low flow from a maintenance problem, but a blocked filter does not explain focal hissing, and checking generator output cannot recover air lost downstream at the connectors. Refitting the vest straps for snug contact addresses the change in body size, but tighter straps cannot stop a connector leak that continues to bleed pressure and weaken vibration. Disconnecting and reseating the hose connectors addresses the hissing leak, but a sealed circuit still cannot transmit energy effectively through a loose vest. An exam caveat is to account for all the cues rather than correcting only the first abnormality, and not to raise pressure to compensate for a leak. For a practical check, run the device while listening along the hoses, confirm quiet, secure connections and a snug two-finger vest fit, then retest for strong palpable vibration and easier expectoration.