Infant warmers and incubators · IW family

Fisher & Paykel Healthcare IW900: troubleshooting and error codes

The ServiceForge knowledge base holds 88 documented symptoms for the Fisher & Paykel Healthcare IW900, with 113 ranked causes, 113 diagnostic checks with test points and expected values, and 36 error codes. Each symptom below shows its causes and the first check; the rest is one connection away. Connect ServiceForge to your AI

Symptoms

See Manual alarm sounding patient safety

Alarm sounds and See Manual indicator displays

Ranked causes

1. Watchdog detects microcontroller fault (common)
2. Thermal cut-out in head switched open due to overheating (occasional)
3. Skin sensor damaged or not fully inserted (occasional)
4. Internal fuses blown, mains lead damaged, or internal harnesses disconnected (occasional)

First check

Consult information mode for specific error code

Test point: Display
Expected: Error code displayed

4 corrective actions and part numbers are in ServiceForge. Connect ServiceForge to your AI

Supply PCB fuses blown high voltage

Electric elevator, power outlet, or accessories not functioning

Ranked causes

1. Fuse F1 open (Electric Elevator Module) (occasional)
2. Fuse F5 open (Power Outlet) (occasional)
3. Fuse F2 or F3 open (Accessories) (occasional)
4. Fuse F4 open (Common accessory fuse) (occasional)

First check

Visually inspect supply PCB fuses on inlet/outlet module back

Test point: Fuses F1, F2, F3, F4, F5 on Supply PCB
Expected: All fuses intact

4 corrective actions and part numbers are in ServiceForge. Connect ServiceForge to your AI

Check baby alarm in manual control mode patient safety

Three possible meanings: Manual mode over 25% power for >15 min, skin temp >39°C, or skin sensor fault

Ranked causes

1. Manual mode at over 25% power for more than 15 minutes (common)
2. Skin temperature exceeds 39°C in manual control mode (occasional)
3. DuoSense skin sensor fault in manual control mode (occasional)

3 corrective actions and part numbers are in ServiceForge. Connect ServiceForge to your AI

See manual alarm high voltage

Software detected hazard and shut down heater, or hardware watchdog detected microcontroller failure, or overheat protector tripped

Ranked causes

1. Software detected hazard and heater shut down (rare)
2. Microcontroller failure detected by hardware watchdog (rare)
3. Overheat protector tripped in heater (rare)

3 corrective actions and part numbers are in ServiceForge. Connect ServiceForge to your AI

Skin temperature reading inaccurate patient safety

Temperature display does not match actual skin temperature or fluctuates erratically

Ranked causes

1. Skin sensor is damaged (occasional)
2. Skin sensor not fully inserted into socket (common)
3. Incorrect sensor type installed (occasional)

First check

Visually inspect skin sensor connection

Test point: J2 DuoSense connector
Expected: Sensor fully seated in socket

1 more check with pass and fail actions, 3 corrective actions, and part numbers are in ServiceForge. Connect ServiceForge to your AI

Bassinet tilts without pulling handle patient safety

Bassinet tilt clutch is too loose; bassinet can be tilted without actuating the rear handle

Ranked causes

1. Bassinet clutch too loose (common)
2. Toothed brake system adjustment needed (occasional)

First check

Attempt to tilt bassinet without using handles

Test point: Bassinet body
Expected: Bassinet cannot be tilted without pulling handles

1 more check with pass and fail actions, 4 corrective actions, and part numbers are in ServiceForge. Connect ServiceForge to your AI

Check Baby alarm patient safety

Alarm indicates infant requires evaluation; in Baby Mode means output at 100% for 15+ min (slow temperature rise); in Manual Mode means output above 25% for 15+ min

Ranked causes

1. Baby slow rising to set temperature (common)
2. Manual Mode output above 25% for 15+ minutes (common)

First check

Determine operating mode (Baby or Manual)

Test point: Mode indicator display
Expected: Baby Mode or Manual Mode

2 more checks with pass and fail actions, 2 corrective actions, and part numbers are in ServiceForge. Connect ServiceForge to your AI

Check baby alarm in servo control mode patient safety

Alarm indicates baby is slow rising to set temperature (Baby Mode: output at 100% for 15+ min) or baby requires attention (Manual Mode: output above 25% for 15+ min)

Ranked causes

1. Baby slow rising to set temperature in Baby Mode (common)
2. Output power above 25% for extended period in Manual Mode (common)

2 corrective actions and part numbers are in ServiceForge. Connect ServiceForge to your AI

Error code E7: Stack Overflow high voltage

Microprocessor stack overflow indicating microprocessor or memory failure; may occur with flickering display

Ranked causes

1. Microprocessor or memory failure on Control PCB (rare)
2. Electrolyte leakage from C22 capacitor on Power PCB (with flickering display) (occasional)

6 corrective actions and part numbers are in ServiceForge. Connect ServiceForge to your AI

Functional check: Warmer head security and rotation

Ensure warmer head is secure and rotates smoothly. Head Pivot Nut may be adjusted if rotation is stiff; Washer Pivot may require replacement if central détente lacks positive engagement.

Ranked causes

1. Head Pivot Nut too tight or too loose (occasional)
2. Washer Pivot worn; détente not positive (occasional)

First check

Visually inspect warmer head for secure mounting

Test point: Head base and column interface
Expected: No visible movement or looseness

1 more check with pass and fail actions, 2 corrective actions, and part numbers are in ServiceForge. Connect ServiceForge to your AI

High Skin Temp alarm patient safety

Alarm indicates infant skin temperature is elevated; in Baby Mode exceeds set temperature by 1.0°C or more; in Prewarm/Manual Mode exceeds 39°C

Ranked causes

1. Baby skin temperature 1.0°C above set temperature in Baby Mode (common)
2. Baby skin temperature exceeds 39°C in Prewarm or Manual Mode (common)

First check

Verify operating mode

Test point: Mode indicator display
Expected: Baby Mode, Prewarm Mode, or Manual Mode

2 more checks with pass and fail actions, 2 corrective actions, and part numbers are in ServiceForge. Connect ServiceForge to your AI

High skin temperature alarm in servo control mode patient safety

Skin temperature exceeds set point or absolute threshold depending on operating mode

Ranked causes

1. Skin temperature exceeds set temperature by 1.0°C or more in Baby Mode (unknown)
2. Skin temperature exceeds 39°C in Prewarm or Manual Mode (unknown)

2 corrective actions and part numbers are in ServiceForge. Connect ServiceForge to your AI

Power Fail alarm caution

Warmer has lost electrical power; flashing Power Fail LED indicates power supply failure or supply wall outlet is switched off

Ranked causes

1. Power switch on but supply wall outlet switched off (common)
2. AC power supply failure or cord disconnection (occasional)

First check

Verify front panel power switch state

Test point: Power switch position
Expected: On position

1 more check with pass and fail actions, 2 corrective actions, and part numbers are in ServiceForge. Connect ServiceForge to your AI

See manual indicator with constant monotone alarm patient safety

Indicator accompanied by continuous monotone alarm sound

Ranked causes

1. Thermal cut-out tripped due to overheating (occasional)
2. Watchdog for microcontroller has detected fault (rare)

First check

Verify thermal cut-out condition

Test point: Thermal cut-out in heater
Expected: Switch closed at normal operating temperature

2 corrective actions and part numbers are in ServiceForge. Connect ServiceForge to your AI

Sensor Disconnect alarm patient safety

Alarm indicates skin temperature sensor malfunction; may show '---' flashing on display; thermistor bead mismatch detected within 25 seconds of plug insertion

Ranked causes

1. Sensor plug not fully inserted into socket (common)
2. Thermistor bead mismatch in DuoSense sensor (occasional)

First check

Inspect sensor display

Test point: Baby Skin Temperature Display
Expected: '---' flashing or normal reading

2 more checks with pass and fail actions, 2 corrective actions, and part numbers are in ServiceForge. Connect ServiceForge to your AI

Sensor disconnect alarm in servo control mode patient safety

Problem detected with skin temperature sensor; sensor plug not fully inserted or thermistor beads within DuoSense sensor do not match

Ranked causes

1. Sensor plug not fully inserted into socket in Baby Mode (common)
2. Thermistor bead mismatch within DuoSense sensor (occasional)

2 corrective actions and part numbers are in ServiceForge. Connect ServiceForge to your AI

Unable to provide stable temperature control in baby/patient mode patient safety

Temperature oscillates or cannot be maintained at set point

Ranked causes

1. Skin sensor poorly attached to patient (common)
2. Heat path disrupted between patient and heating element (occasional)

First check

Verify skin sensor is properly positioned on patient

Test point: Sensor attachment point
Expected: Sensor in direct contact with patient skin, secure

1 more check with pass and fail actions, 2 corrective actions, and part numbers are in ServiceForge. Connect ServiceForge to your AI

Warmer head is not secure or does not rotate smoothly caution

Warmer head is loose or does not pivot smoothly on the column

Ranked causes

1. Head pivot nut is not sufficiently tight (common)
2. Washer pivot détente is not sufficiently positive (occasional)

First check

Head security and rotation

Test point: Warmer head
Expected: Head is secure and rotates smoothly

1 more check with pass and fail actions, 2 corrective actions, and part numbers are in ServiceForge. Connect ServiceForge to your AI

Alarm function check

Verify all alarm indicators flash at startup and alarm sounds correctly

Ranked causes

1. Alarm circuit malfunction or indicator lamp failure (unknown)

First check

Switch Power Switch on

Test point: Power Switch and audio output
Expected: Increasing pitch startup sound begins

1 more check with pass and fail actions, 1 corrective action, and part numbers are in ServiceForge. Connect ServiceForge to your AI

Alarm sounding and mute button not being pressed

Continuous alarm output despite operator presence

Ranked causes

1. Operator has not pressed mute button (common)

First check

Operator presses mute button

Test point: Mute button
Expected: Alarm silences and heat is restored to element

1 corrective action and part numbers are in ServiceForge. Connect ServiceForge to your AI

Alarm sounds and mute button not responding caution

Audible alarm is sounding but pressing mute button does not silence or restore heat

Ranked causes

1. Mute button not pressed during alarm (common)

First check

Verify mute button operation

Test point: Mute button
Expected: Button press acknowledged and alarm silenced

1 corrective action and part numbers are in ServiceForge. Connect ServiceForge to your AI

Base level adjustment required caution

Warmer base or column is not level; straight tie rod adjustment needed

Ranked causes

1. Straight tie rod requires adjustment (occasional)

First check

Check if base and column are level

Test point: Warmer base and column
Expected: Base and column level

1 corrective action and part numbers are in ServiceForge. Connect ServiceForge to your AI

Bassinet cannot be tilted with handle

Bassinet tilt clutch is too tight; handles must be pulled together to tilt bassinet

Ranked causes

1. Bassinet clutch too tight (common)

First check

Attempt to tilt bassinet with rear handle

Test point: Bassinet rear handle
Expected: Bassinet tilts freely when handle pulled

3 corrective actions and part numbers are in ServiceForge. Connect ServiceForge to your AI

Calibration check of mains voltage display

Verify that the warmer's top display reads the calculated mains voltage percentage within tolerance

Ranked causes

1. Calibration drift or display error (unknown)

First check

Measure mains voltage at wall outlet

Test point: Wall outlet supplying warmer
Expected: 100V, 120V or 230V nominal
Tools: Calibrated voltmeter

1 more check with pass and fail actions, 1 corrective action, and part numbers are in ServiceForge. Connect ServiceForge to your AI

Calibration check of temperature display

Verify that the skin temperature display reads accurately within specified tolerance

Ranked causes

1. Temperature sensor or display calibration drift (unknown)

First check

Inspect skin sensor lead and sensor head condition

Test point: Skin sensor assembly
Expected: No visible damage or degradation

2 more checks with pass and fail actions, 1 corrective action, and part numbers are in ServiceForge. Connect ServiceForge to your AI

Calibration: Base height adjustment

Bassinet height requires change between 90.5 cm and 100.5 cm

Ranked causes

1. Preset base requires height repositioning (occasional)

First check

Verify hole alignment on base adjustment bar and legs

Test point: Base adjustment bar holes and leg holes
Expected: Holes aligned at selected height (90.5 or 100.5 cm)

1 corrective action and part numbers are in ServiceForge. Connect ServiceForge to your AI

Calibration: Base level adjustment

Base or column not level on elevator base models

Ranked causes

1. Tie rod misalignment or incorrect length (occasional)

First check

Visually verify base and column level using spirit level

Test point: Base top surface and column vertical line
Expected: Level in all directions

1 corrective action and part numbers are in ServiceForge. Connect ServiceForge to your AI

Calibration: Bassinet brake adjustment patient safety

Bassinet tilts without pulling handles or handles pulled together without tilt

Ranked causes

1. Brake cable tension incorrect (common)

First check

Verify bassinet brake engage/release function

Test point: Rear handles and bassinet
Expected: 2mm play in lower handle when adjusted

1 corrective action and part numbers are in ServiceForge. Connect ServiceForge to your AI

Calibration: EIN #4 check

Verify warmer calibration using EIN #4 parameter with thermistor value

Ranked causes

1. EIN #4 calibration out of specification (common)

First check

Read EIN #4 parameter from warmer

Test point: Warmer EIN #4 setting
Expected: 3950, ±20

1 corrective action and part numbers are in ServiceForge. Connect ServiceForge to your AI

Calibration: Information Mode entry and exit

Access Information Mode for diagnostics and calibration using front panel controls; intended for technical personnel only

Ranked causes

1. Need to access calibration and diagnostic information (common)

First check

Depress and hold power mode button

Test point: Prewarm, Manual, or Baby button
Expected: Button held pressed

2 more checks with pass and fail actions, 1 corrective action, and part numbers are in ServiceForge. Connect ServiceForge to your AI

Calibration: Temperature measurement check

Verify warmer temperature measurement accuracy using test probe and check water temperature

Ranked causes

1. Temperature calibration required (common)

First check

Measure warmer temperature with calibrated probe

Test point: Warmer test water
Expected: 36.7°C ± 0.1°C, ±0.1°C

1 corrective action and part numbers are in ServiceForge. Connect ServiceForge to your AI

Castor angle not vertical caution

Castor is not perpendicular to floor; link arm adjustment needed

Ranked causes

1. Link arm requires adjustment (occasional)

First check

Visually inspect castor angle relative to floor

Test point: Castor wheel
Expected: Castor perpendicular to floor

1 corrective action and part numbers are in ServiceForge. Connect ServiceForge to your AI

Check internal fuses, mains lead and harnesses high voltage

Procedure to diagnose defective electrical connections or failed fuses

Ranked causes

1. Open fuse or defective internal harness connection (occasional)

First check

Inspect all internal fuses for continuity

Test point: Fuses F1-F5
Expected: All fuses intact and showing continuity
Tools: Multimeter set to ohms function

2 more checks with pass and fail actions, 1 corrective action, and part numbers are in ServiceForge. Connect ServiceForge to your AI

Control PCB malfunction caution

Controller unresponsive, no display, or erratic behavior

Ranked causes

1. Control PCB failed or damaged (rare)

1 corrective action and part numbers are in ServiceForge. Connect ServiceForge to your AI

Control PCB or Power PCB defective caution

Defective printed circuit board causing loss of function or spurious alarms

Ranked causes

1. Control PCB or Power PCB hardware failure or component damage (rare)

First check

Obtain error code from information mode to identify faulty component

Test point: Display
Expected: Error code indicating PCB fault location

1 corrective action and part numbers are in ServiceForge. Connect ServiceForge to your AI

Controller fuses blown high voltage

Unit loses power or displays malfunction after electrical fault

Ranked causes

1. Fuse F1, F2, F3, F4 or F5 open on power PCB (common)

First check

Visually inspect fuses F1 through F5 on power PCB

Test point: Power PCB fuses F1-F5
Expected: Fuse wire intact and metallic

1 corrective action and part numbers are in ServiceForge. Connect ServiceForge to your AI

CosyCot base to column bolts are not fully tightened caution

Base to column bolts on CosyCot warmer are loose

Ranked causes

1. Base to column bolts are loose (common)

First check

Base to column bolt torque

Test point: Four base to column bolts (43) on CosyCot base
Expected: 12-14 Nm, 12-14 Nm

1 corrective action and part numbers are in ServiceForge. Connect ServiceForge to your AI

Error code E1-E2: Temperature Multiplexer high voltage

Temperature multiplexer not responding correctly; temperature measurement failure indicated

Ranked causes

1. Temperature multiplexer circuit fault on Control PCB (rare)

2 corrective actions and part numbers are in ServiceForge. Connect ServiceForge to your AI

Error code E5: Beads Shorted patient safety

Two thermistor beads in DuoSense skin sensor detected shorted together; sensor malfunction or internal unit short circuit

Ranked causes

1. DuoSense skin sensor thermistor beads shorted (occasional)

4 corrective actions and part numbers are in ServiceForge. Connect ServiceForge to your AI

Flowmeter accuracy is out of specification caution

Flowmeter flow test at 8 LPM shows reading outside acceptable range

Ranked causes

1. Flowmeter calibration is incorrect (occasional)

First check

Flowmeter flow test

Test point: Flowmeter outlet
Expected: 7.5 - 8.5 LPM at test setting 8 LPM, 7.5 - 8.5 LPM

1 corrective action and part numbers are in ServiceForge. Connect ServiceForge to your AI

Fluorescent tubes fail to light

Tubes do not illuminate when lamp head is switched on

Ranked causes

1. Faulty starter fails to trigger tubes (common)

First check

Verify lamp head is powered and switched on

Test point: Lamp power connection and switch
Expected: Lamp head powered on

1 more check with pass and fail actions, 1 corrective action, and part numbers are in ServiceForge. Connect ServiceForge to your AI

Fluorescent tubes flicker excessively on startup

Lamps flicker for an extended period when switched on

Ranked causes

1. Faulty starter (common)

First check

Observe fluorescent tube startup behavior

Test point: Outer fluorescent tubes
Expected: Tubes light without excessive flicker

1 corrective action and part numbers are in ServiceForge. Connect ServiceForge to your AI

Gas hose shows signs of wear, damage or deterioration caution

Visual inspection reveals wear, damage, deterioration, or movement of crimped components on gas hose or o-rings

Ranked causes

1. Gas hose is worn, damaged or deteriorated (occasional)

First check

Gas hose visual inspection

Test point: Gas hose and o-rings
Expected: No visual signs of wear, damage, deterioration or movement of crimped components

1 corrective action and part numbers are in ServiceForge. Connect ServiceForge to your AI

Gas supply regulator output pressure is out of specification caution

Oxygen or air regulator output pressure does not meet required specification

Ranked causes

1. Regulator output pressure is incorrect (occasional)

First check

Regulator output pressure verification

Test point: Regulator output
Expected: 60±5 psi (414±34 kPa) or 50±5 psi USA, ±5 psi
Tools: Independent pressure gauge

1 corrective action and part numbers are in ServiceForge. Connect ServiceForge to your AI

Halogen lamp not illuminating caution

Lamp fails to light during warmer operation

Ranked causes

1. Halogen lamp end of life (common)

1 corrective action and part numbers are in ServiceForge. Connect ServiceForge to your AI

Heater output control calibration caution

Verify heater element responds correctly to power level adjustments

Ranked causes

1. Heater control circuit malfunction or power output stuck at non-zero (unknown)

First check

Select Manual Mode and set power to 0%

Test point: Power bar display and heater element
Expected: All power bar segments extinguished, no heat output

2 more checks with pass and fail actions, 1 corrective action, and part numbers are in ServiceForge. Connect ServiceForge to your AI

Internal fuse blown or mains lead defective high voltage

Loss of power or partial functionality due to open fuse or damaged mains connection

Ranked causes

1. Blown fuse F1, F2, F3, F4, or F5; damaged mains lead; or loose internal harness (common)

First check

Inspect all internal fuses for continuity

Test point: Fuses F1, F2, F3, F4, F5 on Power PCB
Expected: All fuses intact and conducting

2 more checks with pass and fail actions, 1 corrective action, and part numbers are in ServiceForge. Connect ServiceForge to your AI

LED warning light malfunction

LED warning light does not respond correctly to light intensity changes or does not illuminate when expected

Ranked causes

1. LED warning light circuit fault or sensor malfunction (rare)

First check

Position finger near blue light sensor

Test point: Blue sensor location near outer fluorescent tube
Expected: LED does not light at 10 cm distance

1 more check with pass and fail actions, 1 corrective action, and part numbers are in ServiceForge. Connect ServiceForge to your AI

Light control check

Verify light button controls warming head lamp on and off

Ranked causes

1. Light control circuit malfunction or lamp failure (unknown)

First check

Press Light Button to turn light on

Test point: Light Button and halogen lamp
Expected: Light turns on

1 more check with pass and fail actions, 1 corrective action, and part numbers are in ServiceForge. Connect ServiceForge to your AI

Low Skin Temp alarm patient safety

Alarm indicates infant skin temperature is below target; set temperature exceeds baby skin temperature by at least 1.0°C in Baby Mode only

Ranked causes

1. Baby skin temperature 1.0°C below set temperature in Baby Mode (common)

First check

Verify operating mode is Baby Mode

Test point: Mode indicator display
Expected: Baby Mode

1 more check with pass and fail actions, 1 corrective action, and part numbers are in ServiceForge. Connect ServiceForge to your AI

Low skin temperature alarm in servo control mode patient safety

Set temperature exceeds baby skin temperature by 1.0°C or more in Baby Mode; alarm disabled for 15 min after Baby Mode start and when skin temp within 0.5°C of set point

Ranked causes

1. Set temperature exceeds baby skin temperature by 1.0°C or more (unknown)

1 corrective action and part numbers are in ServiceForge. Connect ServiceForge to your AI

Microcontroller watchdog fault detected patient safety

Hardware watchdog monitor has detected microcontroller failure and reset system

Ranked causes

1. Microcontroller not toggling watchdog pin regularly; watchdog resets system (rare)

First check

Observe watchdog reset pattern and error codes

Test point: Display and See Manual indicator
Expected: No repeated resets; stable operation without watchdog errors

1 corrective action and part numbers are in ServiceForge. Connect ServiceForge to your AI

Mobile warmer stabiliser weight bolt is not secure caution

Stabiliser weight bolt on mobile warmer base is loose

Ranked causes

1. Stabiliser weight bolt is loose (common)

First check

Stabiliser weight bolt tightness

Test point: Stabiliser weight bolt (18) on mobile warmer base
Expected: Bolt is fully tightened and secure

1 corrective action and part numbers are in ServiceForge. Connect ServiceForge to your AI

Over temperature condition detected patient safety

Skin temperature exceeds safe threshold causing comparator to disable heater

Ranked causes

1. Temperature exceeds 39.5°C threshold; hardware safety comparator activates (common)

First check

Measure skin temperature at sensor input

Test point: Skin sensor (J2)
Expected: Below 39.5°C, Safety disable above this

1 corrective action and part numbers are in ServiceForge. Connect ServiceForge to your AI

Power fail alarm check

Verify power fail alarm sounds and indicator flashes when mains power is removed

Ranked causes

1. Power fail detection circuit or alarm output failure (unknown)

First check

Unplug power cord from wall supply

Test point: Power cord and wall outlet
Expected: Warmer switches to battery/UPS backup

1 more check with pass and fail actions, 1 corrective action, and part numbers are in ServiceForge. Connect ServiceForge to your AI

Power fail alarm flashing

Power fail LED flashing and pulsing alarm sounding when mains power is interrupted

Ranked causes

1. Mains power switch turned off at wall outlet (common)

First check

Verify mains power switch position at wall outlet

Test point: Wall outlet switch
Expected: Switch in ON position

1 corrective action and part numbers are in ServiceForge. Connect ServiceForge to your AI

Power fail condition - battery backup activated

Mains power has failed; super capacitor C22 providing backup power for alarm

Ranked causes

1. Mains power loss while unit switched on; super capacitor energizes backup alarm (occasional)

First check

Verify mains power availability at wall outlet

Test point: Wall outlet
Expected: Mains AC voltage present at outlet

1 corrective action and part numbers are in ServiceForge. Connect ServiceForge to your AI

Power mode button indicator check

Verify each power mode button illuminates its respective indicator when pressed

Ranked causes

1. Power mode button indicator circuit malfunction or LED failure (unknown)

First check

Press Prewarm button

Test point: Prewarm button and indicator LED
Expected: Prewarm indicator lights

2 more checks with pass and fail actions, 1 corrective action, and part numbers are in ServiceForge. Connect ServiceForge to your AI

Power PCB malfunction high voltage

Unit does not power on or loses power intermittently

Ranked causes

1. Power PCB failed or damaged (rare)

1 corrective action and part numbers are in ServiceForge. Connect ServiceForge to your AI

Power-fail alarm operates for less than 12 minutes patient safety

Power-fail indicator flashes and audible alarm sounds for less than 12 minutes when warmer is turned on after power loss

Ranked causes

1. Power-fail supercapacitor has insufficient charging ability (common)

First check

Power-fail alarm duration test

Test point: Front panel power switch, wall power socket
Expected: Power-fail indicator flashes and audible alarm sounds for at least 12 minutes

1 corrective action and part numbers are in ServiceForge. Connect ServiceForge to your AI

More symptoms

Replacement: Balance spring
Replacement: Bassinet corner caps
Replacement: Castors (IW910/IW920 models)
Replacement: Castors (IW93x/IW95x models)
See Manual alarm (constant LED with pulsing tone)
See Manual alarm (constant LED with steady tone)
See Manual alarm (flashing LED)
See manual alarm spurious
See manual indicator flashing
See manual indicator flashing with constant monotone alarm
See manual indicator with rapid pulsing two-tone alarm
See Manual indicator with rapid two-tone pulsing alarm
Skin sensor damaged or incorrectly inserted
Skin sensor is damaged or incorrectly installed
Skin temperature measurement is not accurate
Stuck button error test
System calibration check EIN #4 is out of specification
System calibration check EIN #5 is out of specification
Temperature reference check (EIN #4)
Thermal cut-out tripped in heater element
Timer and Apgar function check
Unable to maintain stable skin temperature control in baby/patient mode
Unable to provide stable skin temperature control in baby/patient mode
Uncontrolled full power applied to heating element
Unit does not power on
UPS battery run time is less than 8 minutes
Warmer alarm sounding continuously without mute response
Warning light illuminates during operation

28 more symptoms with ranked causes and checks are in ServiceForge. Connect ServiceForge to your AI

Error codes

Code	Meaning	Trigger	Severity
`0`	No error has occurred.	Normal operation	info
`0`	NONE	No error condition	info
`11`	BUTTON MUX	Button multiplexer malfunction	error
`11`	Button multiplexer is not responding correctly. Buttons cannot be sensed.	Button multiplexer failure	error
`1-2`	Temperature multiplexer not responding correctly; temperature cannot be measured.	Temperature measurement failure	error
`1-2`	TEMPERATURE MUX	Temperature multiplexer malfunction	error
`13`	BAD FREQUENCY	Mains power frequency not sensed at startup	warning
`13`	Bad Frequency - device could not sense mains power supply frequency at power up	Mains frequency sensing failure at power up	error
`14`	Failed ADC - regular ADC conversions failed to complete normally	ADC conversion timeout	critical
`14`	FAILED ADC	ADC conversion failed to complete in normal time	critical
`15`	LED TOGGLE	Display driver U1 detected faulty	error
`15`	Bad LED Toggle - display driver U1 detected as faulty	Display driver U1 failure	error
`16`	Buffer Overflow - RS232 serial communications buffer overflowed	Serial buffer overflow condition	warning
`16`	BUFFER OVERFLOW	RS232 serial buffer overflow detected	error
`17`	MISSING PULSES	Triac delivering insufficient or uncontrolled power to element	error
`17`	Missing Triac Firing - triac delivering insufficient or uncontrolled power to heater element	Triac firing detection failure	error
`17`	Heater control circuit fault or over-temperature protection activated	Over-temperature comparator disables heater or 100% output monitor detects uncontrolled power	error
`17`	Microcontroller unable to control heater element power or over-temperature safety comparator has disabled heating	Hardware safety circuits detect loss of element power control or temperature exceeds 39.5°C without software alarm	critical
`17`	Heater control loss	Over temperature comparator disables heater or 100% output monitor detects uncontrolled power	error
`18`	Spurious Triac Firing - triac delivering additional or uncontrolled power to element	Spurious triac firing detection	warning
`18`	SPURIOUS PULSES	Triac delivering additional or uncontrolled power to element	error
`19`	RELAY OUT	Relay opened due to continuous full power or watchdog failure	critical
`19`	Relay Out - relay which isolates element detected as opened	Relay open circuit detected	error
`20-28`	EEPROM Error - non-volatile memory problem detected	Non-volatile memory error detected	warning
`30`	Not Configured - device configuration not selected in EEPROM	Missing or invalid device configuration	error
`31`	Stuck Button - one of the front panel buttons is stuck down	Button held down during power-up or physical sticking	warning
`34`	Light Circuit Faulty - light detected on when it should be off	Light control or sense circuit failure	warning
`35`	Temperature Problem - temperature reference measurements out of tolerance	Temperature reference measurement failure	error
`36`	Not configured; device configuration in EEPROM changed.	Configuration change detection at startup	critical
`5`	Thermistor beads in DuoSense skin sensor shorted together.	Sensor short circuit detected	error
`5`	BEADS SHORTED	Thermistor beads in DuoSense skin sensor detected shorted	error
`7`	STACK OVERFLOW	Microprocessor stack overflow detected	critical
`7`	Microprocessor stack overflow indicating microprocessor or memory failure.	Stack overflow detection	critical
`E1-E2`	Temperature Multiplexer	Temperature multiplexer circuit fails to respond or communicate	error
`E5`	Beads Shorted	Two thermistor beads in DuoSense skin sensor detect as shorted to each other	warning
`E7`	Stack Overflow	Microprocessor stack memory overflows during operation	error

Likely causes and actions for each code are in ServiceForge. Connect ServiceForge to your AI

Community

0 fixes logged by technicians through their AI, with outcomes, for this model.

ServiceForge knowledge base record. Field-unverified unless technicians confirmed it. A teaching summary of the record, not a service manual. Export 2026-10-14.