|
(b)(6).Method: the pcb from the subject mr850 respiratory humidifier was received at fisher & paykel (f&p) healthcare in new zealand for investigation, where it was performance tested.Our investigation is thus based on the evaluation of the subject device, the information provided by the customer, previous investigations of similar complaints, and our knowledge of the product.Results: performance testing of the returned pcb from the subject mr850 respiratory humidifier, confirmed that no sound was generated from the speaker.Resistance testing identified an open circuit in the speaker's coil.Conclusion: the root cause of the speaker failure was due to an open circuit in the speaker coil.The mr850 respiratory humidifier product technical manual contains a maintenance schedule which instructs the user to conduct annual visual checking and performance testing of the mr850 respiratory humidifier.In addition, the product technical manual also states that "all servicing procedures should be followed by a humidifier test, and an electrical safety test to ensure proper operation".The mr850 respiratory humidifier is equipped with visual alarm indicators in addition to the audible alarm.
|