Fisher & Paykel MR850 6.2Technical Problems

Symptom	Corrective Action		Reference
A low temperature	1.	Make sure the humidifier has had time to warm up and that
is shown on the		there is sufficient gas flow through the breathing circuit.
humidifier’s
	2.	The humidifier cannot maintain temperature. If the	Section 4.5
display, with no		temperature indicator is also on then an alarm will occur
audible alarm		eventually.
	3.	Humidifier or probe faulty. Complete humidifier and probe	Section 8
		performance test. Replace probe or service humidifier as
		required.
High displayed	1.	Flow has recently been changed, allow 30 minutes for
temperature, no		temperature to stabilise
temperature alarm	2.	Manual or automatic humidity compensation is active	Section 4.1.5
Temperature		The gas flow rate may have suddenly changed. Monitor	Section 8
indicator flashes,		the displayed temperature, if the temperature does not fall
with audible alarm,		rapidly then remove humidifier from patient, and complete a
and a high		performance test on the humidifier, and temperature / flow
temperature is		probe. Replace probe or service humidifier as required.
shown.

6.2Technical Problems

Problems that cause the humidifier to malfunction without an audible alarm are discussed in this section.

Symptom	Corrective Action		Reference
See manual	1.	Check that the mains supply is within specification.
indicator lit (not		Provide adequate mains supply if required.
flashing)	2.	If ‘PtS’ is displayed.	Section 6.1
	3.	Replace PCBs.	Section 7.2.3
Humidifier will not	1.	Humidifier plugged into mains supply?
turn on with on/off	2.	Check that the mains supply is within specification.
button, and no		Provide adequate mains supply if required.
indicators are lit	3.	Remove mains power and check the fuses.	Section 7.2.2
	4.	Check continuity of mains power cord. Replace as	Section 7.2.7
		necessary.
	5.	Check the transformer windings are not open circuit.	Section 7.2.4
		Primary Winding: Red wires
		Secondary 10v winding: White wires
		Secondary 22v winding: Yellow wires
		If any windings are open circuit, replace the transformer.
	6.	Replace PCBs.	Section 7.2.3
Unit fails		Send unit to a Fisher & Paykel Healthcare service	Section 7.2.3
calibration check		representative for calibration, or replace PCBs.
Probe fails Probe		Replace probe.
Accuracy Check
Unit fails to reach	1.	If the chamber outlet temperature was low, the heater plate	Section 7.2.5
temperature in		element should be checked. Replace element as
humidifier control		necessary.
check. (Section	2.	If the airway temperature was low, replace breathing circuit
8.1.4)		and re-test.
	3.	Replace PCBs.	Section 7.2.3

26 MR850 Technical Manual * Revision J * Issued November 2005 * Ref. 185041340 (185041713 internal)