Hospital beds · Giraffe family

GE Healthcare Giraffe: troubleshooting and error codes

The ServiceForge knowledge base holds 154 documented symptoms for the GE Healthcare Giraffe, with 314 ranked causes, 138 diagnostic checks with test points and expected values, and 93 error codes. Each symptom below shows its causes and the first check; the rest is one connection away. Connect ServiceForge to your AI

Symptoms

Device will not power up with alarm sound

Device fails to power up and alarm sounds

Ranked causes

1. Defective scale (common)
2. Defective scale harness (occasional)
3. Defective servo oxygen board (occasional)
4. Defective servo oxygen cable (occasional)
5. Defective PF battery (occasional)
6. Defective power supply (occasional)
7. Defective power harness to SBC (occasional)
8. Defective SBC (occasional)
9. Defective control board (rare)

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

System Failure 1 displayed

No Timer2 error; clock battery or scale/harness/Servo Oxygen board/cable/ribbon cable defects indicated

Ranked causes

1. Missing or bad clock battery (common)
2. Defective scale (occasional)
3. Defective scale harness (occasional)
4. Defective Servo Oxygen board (occasional)
5. Defective Servo Oxygen cable (occasional)
6. Defective PF Battery (occasional)
7. Defective 14 pin ribbon cable between control board and SBC (occasional)
8. Defective SBC (occasional)
9. Defective control board (occasional)

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

Humidity Failure Alarm

Motor Drive Failure alarm is on; opens safety relay 2 and disables humidifier

Ranked causes

1. Elevating base does not function; safety relay 2 not energized (common)
2. Humidifier safety thermostat open (common)
3. Defective humidifier heater or humidifier safety thermostat (occasional)
4. No mains voltage at humidifier isolation transformer input (occasional)
5. Defective fuse on relay board rev 10 or higher (occasional)
6. Defective fuse on relay board rev 9 or lower (occasional)
7. Defective relay board (rare)
8. Humidity sensor failed (common)

First check

Check safety relay 2 control signal continuity

Test point: 50-pin ribbon cable, pin 34
Expected: Continuity present

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

System Failure 15 displayed high voltage

Safety Relay 1 test failure; unable to turn heater on or off; sensor, cable, transformer, or board defect

Ranked causes

1. If error occurs during calibration, J1, J2, and J4 not unplugged or JP1 not installed properly (common)
2. Air temperature sensor is above 40C at power-up (occasional)
3. Defective sensor in compartment air probe (occasional)
4. Defective compartment sensor cable (occasional)
5. No output from heater isolation transformer or defective relay board (common)
6. Defective heater isolation transformer (occasional)
7. Defective DAC circuit on control board (occasional)

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

Elevating base will not go up or down

Bed height adjustment mechanism does not respond to controls

Ranked causes

1. Pedal switches disabled on operator or service screen (common)
2. Defective toroidal transformer (occasional)
3. No mains input to toroidal transformer (occasional)
4. Defective fuse on relay board (occasional)
5. Defective 50-pin ribbon cable (occasional)
6. Defective relay board (occasional)

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

Oxygen output below setpoint patient safety

Sensor1 reading more than 3% below oxygen set point 7 minutes after change

Ranked causes

1. Low O2 supply pressure or flow (common)
2. Air leaks into patient compartment (common)
3. Supply valve not opening (occasional)
4. End cap safety valve not opening (occasional)
5. Calibration valve not closing (occasional)
6. Patient compartment vents occluded (occasional)

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

Bed Heater Failure Alarm caution

Software turned on incubator heater but it is not turning on or current sense circuit not detecting it

Ranked causes

1. Bed safety thermostat open (device shut off when heater was hot) (common)
2. Defective incubator heater, thermostat, or wire harness (occasional)
3. Defective incubator solid state relay (SSR) (occasional)
4. Defective 50-pin ribbon cable between relay and control board (occasional)
5. Defective relay board (rare)

First check

Allow device to cool if heater was recently hot

Test point: Incubator
Expected: Temperature below 40ºC, below

2 more checks with pass and fail actions, 6 corrective actions, and part numbers are in ServiceForge. Connect ServiceForge to your AI

Fan Failure Alarm

Fan rotation is not being detected

Ranked causes

1. Fan not turning (common)
2. Fan or fan hub not seated properly (common)
3. Defective fan motor (occasional)
4. Defective relay board (occasional)
5. Optical fan sensor not detecting fan (occasional)

First check

Verify fan hub seating on shaft

Test point: Fan hub and shaft
Expected: Hub fully seated down on shaft

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

ADD WATER message stays on after water added

Add water warning message persists on display even after reservoir is refilled

Ranked causes

1. Defective reservoir switch (common)
2. Defective 50-pin ribbon cable (occasional)
3. Defective relay board (occasional)
4. Defective control board (occasional)

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

Black or dim display

Display is very dark or completely black

Ranked causes

1. LCD backlight cable not fully seated (common)
2. Defective LCD backlight cable (occasional)
3. Defective LCD (occasional)
4. Defective SBC (rare)

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

Display appears white or has distorted image caution

Display shows white screen or image is distorted with improper colors or pixelation.

Ranked causes

1. LCD LVDS cable not fully seated (common)
2. Defective LCD LVDS cable (occasional)
3. Defective LCD display (occasional)
4. Defective single board computer (SBC) (occasional)

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

Display is black or dim caution

Display shows completely black or very dim/dim image. Brightness is too low to see content.

Ranked causes

1. LCD backlight cable not fully seated (common)
2. Defective LCD backlight cable (occasional)
3. Defective LCD display (occasional)
4. Defective single board computer (SBC) (occasional)

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

Display stuck on Giraffe logo screen

Display shows Giraffe logo and does not proceed to operating screen; alarm LED indicators working at power on

Ranked causes

1. 14-pin ribbon cable disconnected (common)
2. Defective ribbon cable (occasional)
3. Defective SBC (occasional)
4. Defective control board (occasional)

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

Oxygen sensor readings out of range patient safety

Oxygen probe failure - sensors out of range or difference >3%

Ranked causes

1. Defective sensor (common)
2. Leak or occlusion in sensor housing (common)
3. Defective cable or connection (occasional)
4. Defective Servo O2 board (rare)

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

Scale icon does not appear on control panel

No scale indicator on display

Ranked causes

1. Scale not plugged in (common)
2. Defective cable (occasional)
3. Defective circuit board (occasional)
4. Defective scale receptacle (occasional)

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

Sensor temperature out of range

Sensor plug thermistor temperature reading outside 15C-55C

Ranked causes

1. Device is too cold (common)
2. Cooling fan not running (occasional)
3. Defective sensor plug thermistor or cable (occasional)
4. Defective Servo O2 board (rare)

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

System Failure 16 displayed high voltage

Incubator heater could not be turned off during Power-on Self Test; SSR or relay board defect

Ranked causes

1. Defective solid state relay (SSR) (common)
2. Defective incubator heater SSR (common)
3. Defective current sense circuit on relay board (occasional)
4. Defective 50-pin ribbon cable (occasional)

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

System Failure 3 displayed

ADC calibration detected a channel out of range; scale, harness, or control board defect

Ranked causes

1. Defective scale (occasional)
2. Defective scale harness (occasional)
3. No line frequency signal or Timer2 of microprocessor defective (occasional)
4. Defective circuit on control board (occasional)

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

Touch screen does not function

User interface touch screen not responding to input

Ranked causes

1. Foreign substance on touch screen surface (common)
2. Touch controller flex cable not fully seated (common)
3. Touch controller USB cable not fully seated (common)
4. Defective touch controller (occasional)

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

User interface touch screen does not function caution

Touch screen is unresponsive to user input or touches. Interface controls cannot be accessed via touch.

Ranked causes

1. Foreign substance on touch screen surface (common)
2. Touch controller flex cable connection not fully seated (common)
3. Touch controller USB cable connection not fully seated (common)
4. Defective touch controller (occasional)

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

White display or distorted image

Display shows white screen or image is garbled/distorted

Ranked causes

1. LCD LVDS cable not fully seated (common)
2. Defective LCD LVDS cable (occasional)
3. Defective LCD (occasional)
4. Defective SBC (rare)

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

Baby Hot alarm activates patient safety

Alarm sounds when patient skin temperature rises above set point; audio suspends for 5-12 minutes when silenced depending on temperature deviation

Ranked causes

1. Baby mode set temperature is incorrect for patient (common)
2. External heat such as phototherapy or sunlight (occasional)
3. Probe disconnected from skin (occasional)

First check

Verify baby mode set temperature setting

Test point: Setup menu
Expected: Temperature appropriate for patient

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

Check SpO2 patient safety

System detects a problem with the SpO2 probe. Display/Light notification with 2 min silence time, medium priority escalating to high after 10 sec.

Ranked causes

1. Defective probe (occasional)
2. Interference (occasional)
3. Too much ambient light (occasional)

First check

Assess ambient light level around probe

Test point: Probe attachment area
Expected: Reduced ambient light exposure

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

Device will not turn on (power fail alarm)

Device does not power up and power fail alarm sounds

Ranked causes

1. No AC power (common)
2. No 12V DC power (common)
3. Defective power supply (occasional)

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

Fan motor not operating or running slowly caution

Incubator fan does not rotate or rotates slowly; poor air circulation; high internal temperature.

Ranked causes

1. Fan motor defective or bearing worn (common)
2. Fan blade or hub stuck or damaged (occasional)
3. Optical fan sensor malfunction (occasional)

First check

Rotate fan blade by hand (power off)

Test point: Fan blade on motor shaft
Expected: Fan rotates freely without grinding or resistance

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

Hands-free alarm silence does not work

Hands-free alarm silence function not responding

Ranked causes

1. Too much ambient sunlight (common)
2. Defective alarm board (occasional)
3. Defective LINCAN cable (occasional)

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

Heater not heating or heating inconsistently caution

Incubator heater or humidifier heater not producing heat or operating erratically

Ranked causes

1. Safety relay 1 not switching heater isolation transformer primary (occasional)
2. Heater current sense circuit failure (rare)
3. Solid state relay (SSR) failure (occasional)

First check

Verify safety relay 1 energization

Test point: Safety relay 1 coil
Expected: Energized when heater demand is active

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

No power fail indicator (red LED)

Power fail red LED is not illuminated

Ranked causes

1. Display power cable disconnected (common)
2. Defective display power cable (occasional)
3. Defective alarm board (occasional)

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

Patient Cold alarm patient safety

Temperature measured by skin probe is 1.0°C below set temperature (or 0.5°C if configured); requires Skin Temperature alarm enabled

Ranked causes

1. Baby Mode set temperature incorrect for patient (common)
2. Probe disconnected from skin (common)
3. Patient is cold (common)

First check

Verify probe attachment to skin

Test point: Patient skin
Expected: Probe firmly attached

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

Patient Hot alarm patient safety

Temperature measured by skin probe is 1.0°C above set temperature (or 0.5°C if configured); requires Skin Temperature alarm enabled

Ranked causes

1. Baby Mode set temperature incorrect for patient (common)
2. External heat such as phototherapy or sunlight (occasional)
3. Skin temperature probe disconnected from skin (common)

First check

Verify skin temperature probe attachment

Test point: Patient skin
Expected: Probe firmly attached to skin

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

Power Failure (LED Indicator)

No AC power into device or 5V power supply not present despite AC power

Ranked causes

1. On/Off switch not turned on (common)
2. Defective fuse F1 or F2 on relay board (common)
3. Defective power supply (occasional)

First check

Verify power cord plugged and switch on

Test point: Power cord, on/off switch, back panel circuit breaker
Expected: Cord in live outlet, switch/breaker on

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

RH Sensor calibration failed

Message displayed when RH sensor signal is outside expected range (65–85% RH), indicating either sensor defect or faulty calibration bottle.

Ranked causes

1. RH sensor signal out of range 65–85% RH (common)
2. RH sensor defective (occasional)
3. Calibration bottle defective (occasional)

First check

Verify calibration setup conditions

Test point: RH sensor environment
Expected: Proper sensor placement, ambient conditions stable

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

RH Sensor Calibration Failed error

Calibration procedure fails with error message indicating RH sensor signal outside expected range

Ranked causes

1. RH sensor signal outside expected range at 65-85% RH (common)
2. Calibration bottle defective (occasional)
3. RH sensor defective (occasional)

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

Scale does not register weight or SC value does not respond to applied weight patient safety

When standard weight is placed on scale, displayed SC value does not increase or increases by incorrect amount

Ranked causes

1. Scale cable routed incorrectly, bent, or pinched (common)
2. Scale tray obstruction from blankets or cushions (common)
3. Scale sensor malfunction or connector disconnection (occasional)

First check

Verify all four shipping screws are removed from screw holes

Test point: Scale assembly screw holes
Expected: All four screw holes empty, no shipping screws present

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

Scale icon disappears/reappears with clicking

Scale indicator flickers with repeated clicking sound

Ranked causes

1. Defective or disconnected cable (common)
2. Defective circuit board (occasional)
3. Defective scale receptacle (occasional)

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

Screen refreshes every few seconds with scale attached

Display constantly refreshes when scale is connected

Ranked causes

1. Defective circuit on control board (occasional)
2. Defective scale (occasional)
3. Defective scale harness (occasional)

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

Servo oxygen system does not calibrate patient safety

System fails to complete oxygen sensor calibration after user initiates procedure; calibration valve may not open or fan may not activate

Ranked causes

1. Calibration valve stuck closed (unknown)
2. Calibration fan not activating (unknown)
3. Oxygen sensors degraded or absent (unknown)

First check

Verify two oxygen sensors are physically present

Test point: Sensor housing beneath bed
Expected: Two fuel cell oxygen sensors installed

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

System Failure 8 displayed

No Line Frequency error; 120 hertz signal missing from control board or relay board circuit defect

Ranked causes

1. Defective control board (common)
2. Defective 50-pin ribbon cable between the relay board and control board (occasional)
3. Defective relay board (occasional)

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

Alarm Board not illuminating or functioning

Red LED not lighting during power fail; beacon lights not responding to commands; buzzer not activating on CAN communication loss

Ranked causes

1. +5V DC STBY power not available to Alarm Board (common)
2. Alarm Board CAN bus communication failure (occasional)

First check

Measure +5V DC STBY voltage at Alarm Board

Test point: Alarm Board power input
Expected: +4.5 to +5.5V DC, +/- 0.5V

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

Baby Cold alarm activated patient safety

Audio alarm with display and light notification when patient skin temperature falls below set temperature in Baby or Manual mode

Ranked causes

1. Baby mode set temperature is incorrect for patient (unknown)
2. Probe disconnected from skin (unknown)

First check

Verify skin temperature probe attachment to patient skin

Test point: skin temperature probe contact point
Expected: Probe firmly attached to patient skin

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

Baby Cold alarm activates patient safety

Alarm sounds on display/light when patient skin temperature falls below set temperature in Baby or Manual mode. Audio suspends for 5–12 minutes when silenced depending on temperature deviation.

Ranked causes

1. Baby mode set temperature is incorrect for patient (common)
2. Probe disconnected from skin (common)

First check

Measure patient skin temperature with probe

Test point: Skin temperature probe
Expected: 1.0°C below set temperature (medium alarm) or 2.0°C below (high priority)

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

Bed Height Pedals Disabled alarm caution

Alarm activates when bed raise or lower pedals are pressed but have been disabled on Service or Setup screen

Ranked causes

1. Bed pedal disabled in Service Mode (common)
2. Bed pedal disabled in Setup screen (common)

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

Bed Raise/Lower Pedal Failure Alarm caution

One of the bed Raise/Lower pedal switches is shorted

Ranked causes

1. Defective bed Raise/Lower pedal switch or harness (common)
2. Defective relay board (occasional)

First check

Check switch continuity at connectors

Test point: Bed Raise/Lower pedal switch connectors
Expected: Correct continuity state for switch position

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

Bed will not lock in tilt position patient safety

Tilt ball not engaged in finger pocket latch. Bed platform cannot be secured in tilted position.

Ranked causes

1. Tilt ball not engaged in finger pocket latch (common)
2. Tilt brake pad failure (occasional)

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

Black display

Display shows no image or is completely black with high priority audio alarm active at power on

Ranked causes

1. Display power cable disconnected (common)
2. Defective display power cable (occasional)

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

Check Baby alarm activates patient safety

Alarm sounds on display/light when radiant heater has been running for 12 minutes at specific power setting in Baby or Manual mode without mode or power adjustment.

Ranked causes

1. Mode has not been changed (occasional)
2. Power setting has not been changed (occasional)

First check

Monitor patient carefully

Test point: Patient condition
Expected: Patient stable and appropriately warmed

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

Compartment Sensor Failure Alarm

Software detected difference in two air thermistors exceeding 0.5°C threshold

Ranked causes

1. Defective compartment air probe or harness (common)
2. Defective control board (occasional)

First check

Measure resistance of two air thermistors

Test point: Control board J1, Pins 1-2 and 3-4
Expected: within about 100 ohms
Tools: Resistance meter

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

Confirm Probe Jack Connection alarm patient safety

Skin temperature probe connection alarm activates; heater may shut down if Check Baby alarm unaddressed for 15 minutes

Ranked causes

1. Skin temperature probe is disconnected from probe panel (common)
2. Malfunctioning probe connector (occasional)

First check

Verify probe connection status

Test point: Probe Panel jack
Expected: Connector fully inserted

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

Device will not switch to baby mode

Baby mode cannot be activated

Ranked causes

1. Skin temperature probe in wrong connector (common)
2. Baby mode disabled on service screen (common)

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

Device with servo-humidity shows RH as 0

Relative humidity reading shows only zero despite servo-humidity capability

Ranked causes

1. Defective humidity sensor (common)
2. Defective control board (occasional)

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

Display is black caution

Display shows completely black screen. No display output even though system appears to be powered.

Ranked causes

1. Display power cable disconnected (common)
2. Defective display power cable (occasional)

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

Display stuck on Giraffe logo with base movement possible

Display frozen on logo screen; E-Base can move down or radiant heater may be on even in closed-bed situation

Ranked causes

1. DC power harnesses disconnected or damaged (common)
2. DC power harnesses damaged (occasional)

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

Elevating base fails to raise or lower bed height caution

Bed does not respond to raise/lower pedal commands; stuck at one height or slow movement.

Ranked causes

1. Elevating base motor or actuator defective (common)
2. Elevating base connector loose or disconnected (occasional)

First check

Visually inspect J-45 connector on relay board for loose contact or corrosion

Test point: J-45 elevating base connector on relay board
Expected: Connector fully seated with no oxidation or loose pins

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

Elevating base motor not operating caution

Elevating base motor does not raise or lower bed; no motor response to control commands

Ranked causes

1. Safety relay 2 not switching elevating base transformer primary (occasional)
2. Elevating base transformer secondary voltage absent or low (rare)

First check

Verify safety relay 2 energization

Test point: Safety relay 2 coil
Expected: Energized when motor control command issued

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

Fan Always in High Speed Alarm

Software cannot read temperature of heat sink sensor in incubator heat sink

Ranked causes

1. Defective heat sink sensor or harness (common)
2. Defective control board (occasional)

First check

Measure heat sink sensor resistance in service mode

Test point: J3 harness pins 1-2 at control board
Expected: Valid sensor resistance per specifications

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

Humidifier heater circuit resistance out of range

Heater resistance measured at J53.1 to J53.3 does not match expected value for device voltage configuration

Ranked causes

1. Heater element open or shorted (common)
2. Safety thermostat stuck open or closed (occasional)

First check

Measure heater resistance at J53.1 to J53.3

Test point: J53, pins 1 and 3
Expected: 72 ohms for 115V devices or 288 ohms for 230V devices
Tools: ohmmeter

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

Incubator heater not operating or insufficient heat caution

Bed fails to reach or maintain set temperature; heater cartridge defective or loose connection.

Ranked causes

1. Heater cartridge defective or failed (common)
2. Heater electrical connector loose or disconnected (occasional)

First check

Visually inspect heater cartridge for cracks, discoloration, or burn marks

Test point: Incubator heater element in heat sink
Expected: No visible damage; uniform color

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

Incubator heater resistance measurement high voltage

Verify incubator heater and bed safety thermostat resistance. Two 115V heaters rated 225W at 104V mounted at opposite ends, connected in parallel. Each heater approximately 48 ohms, parallel combination approximately 24 ohms. Bed safety thermostat in series.

Ranked causes

1. Open circuit or failed heater element (occasional)
2. Bed safety thermostat failure (rare)

First check

Measure combined heater resistance

Test point: Between harness connector pin 4 and black wire at SSR
Expected: Approximately 24 ohms (two 48-ohm heaters in parallel), 18-30 ohms
Tools: Ohmmeter, DMM

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

Insufficient power supply voltage high voltage

Control board power connector voltages below specified thresholds on pins 2, 3, or 4 when measured against pin 1 (ground)

Ranked causes

1. Harness 6600-0701-700 or 2075837-001 defective (pins 2 and 3) (common)
2. Harness 6600-0701-700 defective (pin 4) (common)

First check

Measure voltage between pin 1 and pin 2

Test point: 4-wire power connector, pin 1 (ground) to pin 2
Expected: more than 4.75V
Tools: digital multimeter

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

No alarm LED indicators at power on

Alarm LED lights are not illuminated during power-up sequence

Ranked causes

1. Disconnected LINCAN cable between SBC and alarm board (common)
2. Defective LINCAN cable (occasional)

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

More symptoms

No audio alarm
No SpO2 probe
Oximetry system failure
Oxygen calibration failed
Oxygen level elevated in patient compartment
Oxygen output above setpoint
Oxygen sensors operating temperature exceeds limit
Patient Probe 1 or 2 Failure Alarm
Patient Probe 1 or Patient Probe 2 Failure Alarm
Scale initial power-up SC value is not 10,000
Scale measurement error or drift
Scale weight reading incorrect
Servo oxygen system calibration prompted prematurely
System Failure 12 displayed
Temperature Out of Calibration Alarm
Temperature probe resistance out of specification
Toroidal transformer output voltage low or absent
Up Pedal Pressed Alarm
50-pin ribbon cable continuity fault
Air temperature alarm exceeds 38C or 40C
Baby Cold alarm - high priority activation
Baby Cold alarm high priority triggered
Baby Hot alarm activation criteria and hysteresis
Bed Lower Pedal Pressed alarm
Bed Raise Pedal Pressed alarm
Bed warms up slowly or does not reach temperature
Calibration: Electrical safety and calibration
Calibration: Line voltage
Calibration: Line Voltage after relay board replacement
Calibration: Scale weight accuracy
Calibration: Scale weight measurement
Calibration: Servo oxygen system 21% reference point
Calibration: System and Humidifier after control board replacement
Calibration: System and line voltage
Callback Time Complete alarm activates
Center Weight Check
Chassis cover difficult to remove or misaligned
Check Baby - Heat Off alarm
Clock battery replacement
Confirm Probe Jack Connection alarm activates (Baby mode)
Confirm Probe Jack Connection alarm activates (Manual mode)
Device always powers up in service screen mode
Electrostatic discharge damage to connectors
Fan motor replacement
Fan running at high speed without message
Heat sink sensor thermistor resistance abnormal
High pulse rate alarm
High SpO2 alarm
Hood removal for replacement
Humidifier reservoir crazed
Humidifier reservoir has scaling
Load Cell Check
Loss of mains power
Low pulse rate alarm
Low SpO2 alarm
Motor Drive Failure Alarm
No HFAS indicator (green LED)
No red alarm indicators
No white alarm indicators
No yellow alarm indicators
Noise from speaker on power down
Off Center Weight Check
Oxygen system not calibrated
Oxygen system sensor replacement
Oxygen system supply valve leak test
Oxygen system vent screen replacement
Patient cold or patient hot alarm does not trigger
Patient hot or patient cold alarm in manual mode
Power Failure battery replacement
Power loss detected
Power supply harness cable troubleshooting
Power supply not providing correct voltage
Power supply voltage measurement
Raising and lowering elevating base in service mode
Scale cable routing or pinching issue
Scale cannot be calibrated - times out
Scale does not return weight
Scale exceeds maximum weight in run mode
Scale gives consistently inaccurate weights
Scale gives erratic weight readings
Scale slow to return weight
Scale stuck on screen >45 seconds
Shipping screws not removed from scale
Silenced alarm reactivates after silence time expires
Software upgrade fails
SpO2 probe off baby
System Failure 13 displayed
System Failure 14 displayed
System Failure 2 displayed
System Failure 5 displayed
System Failure 7 displayed
System Failure alarm activates
Temp Probe Failure alarm activates
Weight displays as SC: 40000 on service screen

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

Error codes

Code	Meaning	Trigger	Severity
`70`	System Failure 70	Unknown	unknown
`71`	System Failure 71	Unknown	unknown
`81`	System Failure 81	Unknown	unknown
`82`	System Failure 82	Unknown	unknown
`83`	Unexpected SBC Software problem	SBC software error	error
`85`	System Failure 85	Unknown	unknown
`98`	Overflow	Overflow condition	unknown
`99`	Logic problem on the control board	Control board logic error	error
`Baby Cold`	Patient skin temperature has fallen below set temperature threshold in Baby or Manual mode	Measured skin temperature 1.0°C below set temperature (medium priority) or 2.0°C below set temperature (high priority)	warning
`Baby hot`	Patient skin temperature has risen above the set point threshold	Temperature measured by skin temperature probe is 1.0°C above set temperature (medium priority) or 2.0°C above set temperature (high priority)	warning
`Bed Heater Failure`	Incubator heater not turning on or current sense circuit not detecting it	Heater commanded on but not operating or current not detected	error
`Bed Height Pedals Disabled`	Bed pedal pressed but pedals are disabled in Service or Setup screen	Raise or lower pedal pressed while disabled	info
`Bed Lower Pedal Pressed`	Bed lower pedal pressed during device power-up	Lower pedal pressed while turning on device	info
`Bed Raise/Lower Pedal Failure`	Bed Raise/Lower pedal switch is shorted	Switch continuity indicates short condition	error
`Bed Raise Pedal Pressed`	Bed raise pedal pressed during device power-up	Raise pedal pressed while turning on device	info
`Calibration failed`	Sensors not reading between 23-55mV after 5 minutes in calibration mode	Calibration procedure unable to complete	error
`Callback Time Complete`	Callback timer has reached zero and intervention is due	Callback timer reaches zero	warning
`Check Baby`	Radiant heater has been running continuously at high power for extended period without adjustment	Heater running at 100% power (Baby mode) or >25% power (Manual mode) for >12 minutes	warning
`Check Baby - Heat Off`	Check Baby alarm has remained unaddressed for 15 minutes; heater automatically shuts down	Radiant heater running at 100% power for >15 minutes with Check Baby alarm unaddressed for 3 minutes (Baby mode) or heater at >25% power for >12 minutes with Check Baby unaddressed for 3 minutes (Manual mode)	error
`Check O2 Supply`	After calibration, sensor1 reading not >23% after 20 seconds with both valves open	Oxygen supply verification failure after calibration	warning
`Check SpO2`	System detects a problem with the SpO2 probe	Defective probe, interference, or too much ambient light detected	warning
`Compartment Sensor Failure`	Software detected difference in two air thermistors exceeding 0.5°C	Difference in air thermistors > 0.5ºC	warning
`Confirm Probe Jack Connection`	Skin temperature probe connection to Probe Panel should be checked	Activates in Baby mode when skin temperature probe is unplugged; also in Manual mode when probe is unplugged and Man Temp Alarm enabled	warning
`Confirm Probe Jack Connection (Baby)`	No probe detected in Baby mode	No probe plugged into probe jack	warning
`Confirm Probe Jack Connection (Manual)`	No probe detected with Manual temp alarm enabled	No probe plugged into probe jack and Man temp Alarm set	warning
`Fan Always in High Speed`	Software cannot read temperature of heat sink sensor	Heat sink sensor not responding or invalid reading	error
`Fan Failure`	Fan rotation not being detected	Optical fan sensor not detecting fan rotation	error
`FiO2>26%`	Elevated oxygen levels in patient compartment not controlled by servo O2 system	Oxygen level exceeds 26% during servo control	warning
`High Oxygen`	Sensor1 reading more than 3% above set point	Sensor detects oxygen above desired level	warning
`High Pulse rate`	Baby's pulse rate is above set limit	Pulse rate above the set value	warning
`High SpO2`	Baby's blood oxygen saturation is above set level	Blood oxygen saturation above the set value	warning
`Humidity Failure`	Motor drive failure or humidifier issue; humidifier disabled	Various humidity system faults	error
`Low Oxygen`	Sensor1 reading is more than 3% below oxygen set point	7 minutes after a set point change	warning
`Low Pulse rate`	Baby's pulse rate falls below set limit	Pulse rate below the set value	warning
`Low SpO2`	Baby's blood oxygen saturation falls below set level	Blood oxygen saturation below the set value	warning
`Mains voltage calibration failed`	Entered line voltage differs by 20% or more from measured value	User enters calibration value that deviates >20% from actual measured mains voltage	error
`Motor Drive Failure`	Elevating base motor running when not commanded	Motor detected running without command	error
`No SpO2 probe`	No SpO2 probe is detected at the probe panel connector	System does not detect an SpO2 probe at the probe panel	warning
`O2 Cal Lost-No O2`	Servo oxygen never calibrated, system will not operate	System detects no calibration data on startup	critical
`Oximetry system failure`	Oximetry system has failed	Communication between SpO2 and warmer system is lost	error
`Oxygen Probe Failure`	Sensor reading out of range (23-280mV) or difference between sensors >3%	Sensor(s) malfunction or connection failure	error
`Oxygen System Failure 1`	Sensor plug thermistor temperature out of range 15C-55C	Temperature sensor reading outside valid range	error
`Oxygen System Failure 2`	Humidity reading out of valid range 1-99	Humidity sensor malfunction	error
`Oxygen System Failure 3`	Checksum test failed during power-up	Microcontroller self-test failure	critical
`Oxygen System Failure 4`	Analog to digital converter self test failed	ADC reading of Vtest outside 1.216V-1.254V	critical
`Oxygen System Failure 5`	Check O2 Supply alarm silenced twice, sensor1 still not >23%	Persistent oxygen supply inadequacy	error
`Oxygen System Failure 6`	Giraffe control board cannot communicate with Servo O2 board	Communication error on system startup or during operation	critical
`Oxygen System Failure 7`	Watchdog circuit problem detected during power-up	Power-up self-test failure	critical
`Patient Cold - Check Probe 1`	Temperature measured by skin probe is 1.0°C below set temperature	Skin temperature < set temperature - 1.0ºC (or 0.5ºC if configured)	warning
`Patient Hot - Check Probe 1`	Temperature measured by skin probe is 1.0°C above set temperature	Skin temperature > set temperature + 1.0ºC (or 0.5ºC if configured)	warning
`Patient Probe 1 Failure or Patient Probe 2 Failure`	Probe thermistors show difference exceeding 0.5°C	Thermistor difference > 0.5ºC	warning
`Power Failure (LED Indicator)`	No AC power into device or 5V power supply not present	No AC power or 5V supply failure	critical
`Replace Clock Battery`	Clock battery voltage too low	Battery voltage falls below threshold to maintain time	info
`SpO2 probe off baby`	SpO2 probe is detected but not attached to the baby	System does not detect a SpO2 probe on the baby	warning
`System failure`	Electrical, software, or system failure detected where system cannot continue operation	An electrical failure is detected	critical
`System Failure 0`	Communication error between SBC and control board	Device powered on or during operation	error
`System Failure 1`	No Timer2 error; multiple possible hardware defects	Device powered on or during operation	error
`System Failure 11`	ADC on control board not operating to specification (too slow)	Device powered on or during operation	error
`System Failure 12`	Incorrect control board system software checksum	Device powered on or during operation	error
`System Failure 13`	Defective SRAM on control board	Device powered on or during operation	error
`System Failure 14`	Defective watchdog circuit on control board	Device powered on or during operation	error
`System Failure 15`	Safety Relay 1 test failure; unable to turn heater on or off	Device powered on or during operation; note: if System Failure 22 appears during operation, System Failure 15 should appear at startup	error
`System Failure 16`	Incubator heater could not be turned off during Power-on Self Test	Device powered on or during operation	error
`System Failure 18`	Defective Variables	Detected during system operation	error
`System Failure 19`	No Audio Frequency	Detected during system operation	error
`System Failure 2`	Timer2 too fast error; microprocessor Timer2 circuit defective	Device powered on or during operation	error
`System Failure 20`	Display WDOG Time Out	Detected during system operation	critical
`System Failure 22`	Incubator heater will not turn ON during operation	Heater fails to activate during operation	error
`System Failure 23`	System unable to turn OFF incubator heater during operation	Heater fails to deactivate during operation	error
`System Failure 25`	Fan rotation is not being detected	Optical fan sensor fails to detect fan rotation at power-up or during operation	error
`System Failure 26`	System unable to turn off safety relay 1 during power up tests	Safety relay 1 fails to turn off during power-up self-test	critical
`System Failure 27`	Defective non-volatile memory	Detected during system operation	error
`System Failure 28`	SBC board lost communication with control board during operation	Communication failure between SBC and control boards	critical
`System Failure 29`	Defective signal on control board	Detected during system operation	error
`System Failure 3`	ADC calibration detected a channel out of range	During ADC calibration or startup	error
`System Failure 30`	Mains voltage reading LV1 is outside expected range	Mains voltage outside operating range during power-up or operation	error
`System Failure 33`	Defective RH Solid State Relay	Detected during system operation	error
`System Failure 34`	Software revision level does not match	Control board and SBC board software versions incompatible	warning
`System Failure 35`	Wrong dipswitch setup	Detected during power-up self-test	warning
`System Failure 36`	LV1 differs from LV2 by more than 10% of LV2	Voltage measurement discrepancy detected	error
`System Failure 38`	Door switches indicate heater doors both open and closed simultaneously	Physically impossible door switch state detected	error
`System Failure 5`	Volt reference out of acceptable range (1.171V - 1.259V)	During system calibration or startup	error
`System Failure 55`	SBC board On Line Self Test Failure	Detected during SBC board online self-test	error
`System Failure 6`	Defective overtemp DAC circuit on control board	Device powered on or during operation	error
`System Failure 60`	Line Circuit Failure	Detected during relay board LV2 calibration	error
`System Failure 61`	Unable to recover from power fail	Device cannot recover after power failure	critical
`System Failure 62`	Defective flat ribbon cable between control board and SBC	Ribbon cable connection or integrity issue	error
`System Failure 63`	Control board has incompatible software version	Software version incompatibility detected	warning
`System Failure 7`	1.0 V Thermistor reference voltage out of range (0.951V - 1.049V)	During system calibration or startup	error
`System Failure 8`	No Line Frequency signal detected	Device powered on or during operation	error
`Temperature Out of Calibration`	Calibration data lost or control board defective	Calibration data invalid or control board memory failure	warning
`Temp Probe Failure`	Skin probe thermistor mismatch detected	Difference between probe thermistors >0.5 °C	error
`Up Pedal Pressed`	Bed up pedal pressed during device power-up	Up pedal pressed and held during device startup	info

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

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