Maternal fetal monitors

GE Healthcare Corometrics 250cx: troubleshooting and error codes

The ServiceForge knowledge base holds 97 documented symptoms for the GE Healthcare Corometrics 250cx, with 215 ranked causes, 149 diagnostic checks with test points and expected values, and 19 error codes. Each symptom below shows its causes and the first check; the rest is one connection away. Connect ServiceForge to your AI

Symptoms

Recorder light printing caution

Recorder prints too lightly (intermittently), fetal chart prints barely legible

Ranked causes

1. Inappropriate or wrong chart paper used (common)
2. Paper residue, dust, or material buildup on thermal print head (common)
3. Thermal print head pressure uneven; springs not seated properly (occasional)
4. Recorder door assembly broken or loose causing roller misalignment (occasional)
5. Thermal print head not aligned properly with roller (occasional)
6. Print head voltage incorrect (occasional)
7. Thermal print head defective (rare)
8. Recorder board defective (rare)

First check

Load GE-approved chart paper

Test point: Recorder paper slot
Expected: GE-approved paper (2009828-CAO, DAO, FAO) installed

2 more checks with pass and fail actions, 8 corrective actions, and part numbers are in ServiceForge. Connect ServiceForge to your AI

Recorder prints too lightly

Intermittent or consistent light printing on fetal chart paper making prints barely legible.

Ranked causes

1. Wrong chart paper type used (common)
2. Paper residue or dust on thermal print head (common)
3. Thermal print head springs not seated properly (occasional)
4. Recorder door assembly loose or broken (occasional)
5. Thermal print head misaligned with roller (occasional)
6. Print head voltage incorrect (occasional)
7. Thermal print head defective (rare)
8. Recorder board defective (rare)

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

Dashes displayed in maternal SpO2 area

Dashes (---) shown in MSpO2 area of display

Ranked causes

1. Sensor improperly applied on patient finger (common)
2. Maternal movement (common)
3. Excessive ambient light (occasional)
4. Insufficient signal strength (occasional)
5. Wrong SpO2 sensor type connected (occasional)
6. Sensor defective (occasional)
7. SpO2 module or carrier board defective (rare)

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

Dashes displayed in MSpO2 area patient safety

Dashes (---) shown in MSpO2 display area instead of SpO2 value, indicating signal loss or measurement failure

Ranked causes

1. Sensor improperly applied on patient's finger (common)
2. Maternal movement artifact (common)
3. Excessive ambient light (occasional)
4. Intermediate cable not firmly attached (occasional)
5. Wrong SpO2 sensor type connected (occasional)
6. Sensor defective (occasional)
7. SpO2 module or carrier board defective (rare)

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

Internal pressure parameter measured incorrectly patient safety

Internal uterine pressure (IUP) signal not accurate or not being measured correctly during monitoring

Ranked causes

1. Transducer not properly connected to monitor unit (common)
2. Air bubble in dome or catheter blocked (common)
3. Dome cracked (occasional)
4. Catheter fallen out of place (occasional)
5. Catheter or strain gauge not zeroed (occasional)
6. UA board defective (rare)

First check

Verify transducer connection to monitor

Test point: IUP transducer connector port
Expected: Transducer securely seated

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

Internal pressure parameter not measured correctly patient safety

Internal uterine activity (IUA) pressure reading is inaccurate or not functioning; displayed as ID S5.1

Ranked causes

1. Transducer not properly connected to monitor (common)
2. Air bubble in dome or blocked catheter (common)
3. Dome cracked or damaged (occasional)
4. Catheter out of place (occasional)
5. Catheter or strain gauge not zeroed (occasional)
6. UA board defective (rare)

First check

Inspect transducer connection

Test point: Transducer input connector on monitor
Expected: Connector fully seated and secure

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

CHECK CUFF message displayed patient safety

CHECK CUFF message shown in NIBP area of display

Ranked causes

1. Improper cuff position or loose cuff (common)
2. Maternal movement (common)
3. Hose not properly connected to monitor (air pressure error) (occasional)
4. Neonatal cuff used instead of adult cuff (occasional)
5. NIBP board defective (rare)

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

CHECK CUFF message displayed in NIBP area patient safety

Error message 'CHECK CUFF' appears in non-invasive blood pressure display area on screen

Ranked causes

1. Improper cuff position or loose cuff (common)
2. Maternal movement (common)
3. Hose not properly connected to monitor (occasional)
4. Neonatal cuff used instead of adult cuff (occasional)
5. NIBP board defective (rare)

First check

Verify cuff position and tension on maternal arm

Test point: Blood pressure cuff
Expected: Cuff snug on upper arm at heart level

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

Fetal heart rate not displayed properly patient safety

Monitor does not show FHR on display or display is incorrect when ultrasound transducer connected

Ranked causes

1. Ultrasound transducer not properly connected (common)
2. Transducer not properly positioned on patient (common)
3. Insufficient ultrasound gel applied (common)
4. Ultrasound transducer defective (occasional)
5. Signal cannot be captured due to patient/fetus conditions (occasional)

First check

Verify transducer physical connection to monitor

Test point: Transducer connector port
Expected: Transducer securely seated in port

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

Fetal heart rate not displayed properly with ultrasound transducer connected patient safety

Monitor does not show FHR on display when ultrasound transducer is connected

Ranked causes

1. Ultrasound transducer not properly connected (common)
2. Ultrasound transducer not properly positioned on patient (common)
3. Too little ultrasound gel applied (common)
4. Ultrasound transducer defective (occasional)
5. Ultrasound signal not captured due to patient or fetal conditions (occasional)

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

Internal FECG parameter erratic or not recorded patient safety

FECG parameter shown on display erratically or not being recorded properly on strip chart.

Ranked causes

1. FECG cable not properly connected to monitor unit (common)
2. Attachment pad or leg plate not securely attached to patient (common)
3. Electrode wire not secure in leg plate post (common)
4. Electrode defective or not properly attached (occasional)
5. Attachment pad defective (occasional)

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

Internal FECG parameter erratic or not recording patient safety

FECG signal shown erratically on display or not being recorded to strip chart properly

Ranked causes

1. FECG cable not properly connected to monitor unit (common)
2. Attachment pad or leg plate not securely attached to patient (common)
3. Electrode wire not secure in leg plate post (occasional)
4. Electrode defective or improperly attached (occasional)
5. Attachment pad defective (occasional)

First check

Verify FECG cable connection to monitor unit

Test point: FECG connector port
Expected: Cable securely seated

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

Static noise exists on ultrasound signal

Ultrasound signal shows static or noise interference during operation

Ranked causes

1. Inappropriate or refurbished ultrasound transducer used (common)
2. Environmental noise (common)
3. Active fetus (occasional)
4. Ultrasound transducer defective (occasional)
5. Maternal movement (occasional)

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

TOCO transducer not recording contractions patient safety

Uterine activity (TOCO) signal not appearing on display or strip chart during maternal contractions

Ranked causes

1. TOCO transducer not properly connected to monitor unit (common)
2. TOCO transducer not properly positioned on patient (common)
3. UA reference range exceeded (occasional)
4. No maternal contractions occurring (rare)
5. TOCO transducer defective (occasional)

First check

Verify TOCO transducer connection to monitor

Test point: TOCO connector port
Expected: Transducer securely connected

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

TOCO transducer not recording uterine contractions patient safety

Fetal monitor external uterine activity (UA) display shows no contraction signal; transducer inactive

Ranked causes

1. TOCO transducer not properly connected to monitor unit (common)
2. TOCO transducer not properly positioned on patient (common)
3. Uterine activity reference range exceeded (occasional)
4. No maternal contractions occurring (rare)
5. TOCO transducer is defective (occasional)

First check

Verify TOCO transducer connector seated at monitor

Test point: Transducer connector at monitor unit
Expected: Connector fully inserted and securely latched

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

CHECK TOCO message displayed in UA area patient safety

Error message 'CHECK TOCO' appears in uterine activity display area when UA Reference button is pressed

Ranked causes

1. UA Reference button pressed before circuitry stabilized (common)
2. UA reference range exceeded due to over-tightened belt (common)
3. TOCO transducer defective (occasional)
4. UA board defective (rare)

First check

Verify UA circuitry stabilization delay observed

Test point: Monitor startup or transducer connection timing
Expected: 10 seconds elapsed before pressing UA Reference button

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

CHECK TOCO message displayed when UA Reference button pressed patient safety

Monitor displays 'CHECK TOCO' message in UA area when technician attempts to reset UA reference

Ranked causes

1. UA Reference button pressed before UA circuitry stabilized after power-on (common)
2. Uterine activity reference range exceeded due to belt over-tightening (common)
3. TOCO transducer is defective (occasional)
4. UA board is defective (occasional)

First check

Wait 10 seconds after power-on or transducer connection before pressing UA Reference

Test point: Monitor power state and transducer connection timing
Expected: UA circuitry stabilized; no CHECK TOCO message when reference button pressed after 10-second wait

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

No monitoring functions and power indicator off patient safety

Monitor does not power on; no display or LED illumination when power switch is set to On

Ranked causes

1. Power cord not properly connected (common)
2. No power at outlet (common)
3. Power cord defective (occasional)
4. Fuses open or missing (occasional)

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

CHECK IUP message displayed patient safety

Monitor displays CHECK IUP alert in uterine activity area; indicates pressure measurement problem

Ranked causes

1. Blockage in fluid-filled catheter (common)
2. Fetus pressing on catheter (common)
3. Defective catheter (occasional)

First check

Flush catheter system

Test point: Catheter fluid pathway
Expected: Clear fluid flow without resistance

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

CHECK IUP message displayed in UA area patient safety

Error message 'CHECK IUP' shown in uterine activity display area on screen

Ranked causes

1. Blockage in fluid-filled catheter (common)
2. Fetus pressing directly on catheter (occasional)
3. Catheter defective (occasional)

First check

Flush and zero the catheter

Test point: Catheter fluid path and calibration
Expected: Blockage cleared, zero reading verified

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

Incorrect date and time displayed caution

Monitor displays wrong date and/or time in system clock

Ranked causes

1. Date and time set incorrectly (common)
2. Timekeeping RAM chip defective (rare)
3. Main board defective (rare)

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

MECG parameter erratic or not properly recorded patient safety

MECG signal displayed inconsistently or not recording properly on monitor; erratic or missing data

Ranked causes

2. Electrode gel is dried (common)
6. MECG cable is defective (rare)
7. MECG board is defective (rare)

First check

Verify MECG cable is securely connected to monitor

Test point: MECG cable connector to monitor unit
Expected: Cable securely connected

6 more checks with pass and fail actions, 7 corrective actions, and part numbers are in ServiceForge. Connect ServiceForge to your AI

Monitor does not generate heartbeats or pulse sounds patient safety

No audio output from monitor during operation despite having transducer signal

Ranked causes

1. Audio volume set too low (common)
2. Transducer not connected or loosely connected (common)
3. Inadequate ultrasound gel (common)

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

Monitor shows incorrect date and time

System displays wrong date or time after power-on or during operation

Ranked causes

1. Date and time set incorrectly (common)
2. Timekeeping RAM chip defective (occasional)
3. Main board defective (rare)

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

No heartbeat or pulse sounds generated patient safety

Monitor does not emit audio tones for detected heartbeats or pulses

Ranked causes

1. Audio volume set too low (common)
2. Transducer not connected or loose (common)
3. Inadequate ultrasound gel (common)

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

OVERPRESSURE message displayed patient safety

OVERPRESSURE message shown in NIBP area indicating cuff pressure exceeded over-pressure limit

Ranked causes

1. Cuff pressure exceeded 315 mmHg limit (common)
2. Hose kinked (occasional)
3. Hose blocked (occasional)

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

OVERPRESSURE message displayed in NIBP area patient safety

Error message 'OVERPRESSURE' shown in non-invasive blood pressure display area, indicating pressure limit exceeded

Ranked causes

1. Cuff pressure exceeded over-pressure limit of 315 mmHg ± 15 mmHg (common)
2. Hose kinked (occasional)
3. Hose blocked (occasional)

First check

Restrict maternal limb movement

Test point: Patient arm position
Expected: Limb immobilized and supported

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

Recorder does not function and Record Indicator is off

Recorder inactive with Record Indicator not lit when monitor is powered on

Ranked causes

1. Recorder is off or out of paper (common)
2. Paper-out photosensor out of calibration (occasional)
3. Paper-out photosensor disconnected or defective (occasional)

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

Recorder does not function; indicator off caution

Recorder does not operate and Record Indicator LED is not illuminated

Ranked causes

1. Recorder off or out of paper (common)
2. Paper-out photosensor out of calibration (occasional)
3. Paper-out photosensor disconnected or defective (occasional)

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

Recorder functions but Record Indicator flashes caution

Recorder operates but Record Indicator LED flashes on and off every second

Ranked causes

1. Paper supply low or incorrectly loaded (common)
2. Paper-low photosensor out of calibration (occasional)
3. Paper-low photosensor disconnected or defective (occasional)

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

Recorder Record Indicator flashes on and off every second

Recorder functions but Record Indicator flashes intermittently

Ranked causes

1. Paper supply low or incorrectly loaded (common)
2. Paper-low photosensor out of calibration (occasional)
3. Paper-low photosensor disconnected or defective (occasional)

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

Calibration: Recorder horizontal and vertical offset

Verify recorder trace position and quality on strip chart paper

Ranked causes

1. Recorder horizontal offset out of specification (occasional)
2. Recorder vertical line quality or paper curl defect (occasional)

First check

Run recorder calibration test on strip chart paper

Test point: Calibration traces on paper
Expected: First horizontal trace and vertical lines printed within specification
Tools: GE-approved strip chart paper, Trim Knob Control

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

Dashes shown in MHR/P display area patient safety

MECG reading displays as dashes (– – –) indicating inability to determine maternal heart rate due to insufficient signal or signal loss

Ranked causes

1. Monitor unable to determine MECG due to insufficient signal (common)
2. MECG board is defective (occasional)

First check

Confirm patient is not asystolic and electrodes are firmly secured

Test point: Patient condition and electrode attachment
Expected: Patient has cardiac activity; electrodes firmly adhered to skin

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

Flashing '+' sign in UA field patient safety

Plus sign flashing in uterine activity display area on screen

Ranked causes

1. Relative pressure exceeds 100 (common)
2. UA board defective (rare)

First check

Reset UA reference pressure

Test point: UA Reference button
Expected: Flashing '+' clears after button press between contractions

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

Flashing plus sign in UA field on display patient safety

Fetal monitor shows flashing '+' character in uterine activity display field

Ranked causes

1. Relative pressure reading exceeds 100 units (common)
2. UA board is defective (occasional)

First check

Press UA Reference button between contractions

Test point: UA Reference button and display response
Expected: Flashing + disappears; UA display returns to normal reading

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

Recorder does not function and Record Indicator is on

Recorder inactive with Record Indicator illuminated when monitor is powered on

Ranked causes

1. Recorder stepper motor defective (occasional)
2. Recorder roller defective (occasional)

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

Recorder not functioning; Record Indicator on caution

Recorder does not operate but Record Indicator LED remains illuminated

Ranked causes

1. Recorder stepper motor defective (occasional)
2. Recorder roller defective (occasional)

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

REPAIR message displayed patient safety

REPAIR message shown in NIBP area

Ranked causes

1. NIBP pump defective (occasional)
2. System error or self-test failure in NIBP or main board (occasional)

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

REPAIR message displayed in NIBP area patient safety

Repair request message 'REPAIR' shown in non-invasive blood pressure display area indicating service needed

Ranked causes

1. NIBP pump defective (occasional)
2. System error or self-test failure (occasional)

First check

Verify NIBP pump functionality

Test point: NIBP pneumatic system
Expected: Pump cycles during BP measurement attempt

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

SYSTEM FAULT:SOFTWARE error message displayed patient safety

Monitor displays error message 'SYSTEM FAULT:SOFTWARE error' on startup

Ranked causes

1. SW1 switch #7 incorrectly set (common)
2. Software error (unknown)

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

SYSTEM FAULT:UI KEYPAD error message displayed patient safety

Monitor displays error message 'SYSTEM FAULT:UI KEYPAD error' on startup

Ranked causes

1. Main-keypad communication problem (occasional)
2. UI keypad board defective (occasional)

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

Volume of ultrasound tone is low

Ultrasound audio output volume is insufficient during operation

Ranked causes

1. Tone volume set low (common)
2. Dual ultrasound board out of calibration (occasional)

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

Blood pressure high reading patient safety

Blood pressure measurement displays higher than expected; measurement artifact or measurement taken during uterine contraction

Ranked causes

1. Measurement taken during uterine contraction (common)

First check

Verify measurement was taken between uterine contractions

Test point: Contraction monitor display and BP reading correlation
Expected: BP reading taken during low-contraction period (baseline)

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

Blood pressure reading high patient safety

NIBP displays elevated pressure value

Ranked causes

1. Measurement taken during uterine contraction (common)

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

Calibration: MHR/P alarm limits and response

Verify maternal heart rate/pulsatile alarm thresholds (60–120 bpm) and alarm tone behavior (silence, re-alarm timing) using fetal simulator

Ranked causes

1. Alarm limit calibration and functional verification required (common)

First check

Test high alarm threshold activation

Test point: Monitor display; rear panel speaker
Expected: No alarm tone at 119 bpm, no alarm at 120 bpm, alarm tone at 121 bpm
Tools: CorometricsTM 325 simulator with Manual Adjustment knob

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

Calibration: NIBP overpressure detection caution

Verify NIBP overpressure detection triggers at correct pressure range (300–330 mmHg)

Ranked causes

1. Overpressure detection out of specification (occasional)

First check

Set NIBP to overpressure detection test mode

Test point: Mode selector in NIBP Calibration screen
Expected: OVP Test mode selected; monitor closes valves
Tools: Trim Knob Control

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

Calibration: NIBP system patient safety

Non-invasive blood pressure subsystem requires periodic verification and checkout after service work

Ranked causes

1. Routine maintenance interval or post-service verification required (common)

First check

Perform NIBP calibration check

Test point: NIBP subsystem
Expected: Calibration within specification

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

Calibration: NIBP system leakage

Verify NIBP pneumatic circuit does not leak more than specification

Ranked causes

1. System leakage exceeds 6 mmHg/min specification (occasional)

First check

Set NIBP to leakage test mode

Test point: Mode selector in NIBP Calibration screen
Expected: Leak Test mode selected
Tools: Trim Knob Control

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

Calibration: NIBP transducers

NIBP pressure readings inaccurate; verification shows values outside ±2 mmHg pass range compared to external manometer

Ranked causes

1. NIBP transducers out of calibration (common)

First check

Verify NIBP transducer accuracy

Test point: PT1 and PT2 on monitor display vs external manometer
Expected: Within ± 2 mmHg (0.3 kPa) of external manometer reading at ~200 mmHg cuff inflation, ±2 mmHg
Tools: External manometer capable of reading to 350 mmHg, adult cuff, 3 inch rigid cylinder, 12-foot NIBP hose, hand pump bulb

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

Calibration: Recorder offsets caution

Verification of recorder paper feed calibration and signal offset values for accurate waveform display

Ranked causes

1. Annual maintenance or post-service verification of recorder assembly (occasional)

First check

Verify recorder calibration offsets

Test point: Recorder offset adjustment
Expected: Offsets within calibration specification

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

Calibration: Recorder paper-load photosensor caution

Verify and adjust paper-load photosensor voltage output to specification

Ranked causes

1. Paper-load photosensor voltage out of specification (occasional)

First check

Load GE-approved paper without black squares, minimum 9 sheets

Test point: Recorder paper loaded in recorder
Expected: No black squares visible; at least 9 sheets of strip chart paper loaded
Tools: GE-approved strip chart paper

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

Calibration: Recorder paper-low photosensor caution

Verify and adjust paper-low photosensor voltage output to specification

Ranked causes

1. Paper-low photosensor voltage out of specification (occasional)

First check

Load GE-approved paper without black squares

Test point: Recorder paper surface
Expected: No black squares visible; paper advanced for tension
Tools: GE-approved strip chart paper

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

Calibration: Recorder paper-out photosensor caution

Verify and adjust paper-out photosensor voltage output to specification

Ranked causes

1. Paper-out photosensor voltage out of specification (occasional)

First check

Load GE-approved paper without black squares

Test point: Recorder paper surface
Expected: No black squares visible; paper advanced for tension
Tools: GE-approved strip chart paper

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

Calibration: Recorder photosensors caution

Optical sensor verification for recorder assembly to ensure accurate paper feed and signal detection

Ranked causes

1. Scheduled maintenance or post-service checkout of recorder assembly (occasional)

First check

Perform recorder photosensors check

Test point: Recorder photosensor assembly
Expected: Sensors operating and properly aligned

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

Calibration: Recorder vertical offset adjustment caution

Recorder prints horizontal traces with offset outside acceptable range; adjust using trim knob and set screws

Ranked causes

1. Recorder assembly misaligned (common)

First check

Remove top cover

Test point: Top cover fasteners
Expected: Cover removed

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

Calibration: Ultrasound input signal verification

Verify ultrasound signal input to monitor via simulator cable, FHR1 display, heartbeat indicator, audio output, and recorder strip chart output at baseline and variable heart rates.

Ranked causes

1. Ultrasound input signal not properly configured or verified (unknown)

First check

Verify FHR1 value display

Test point: FHR1 display on monitor
Expected: 120 bpm

7 more checks with pass and fail actions, 7 corrective actions, and part numbers are in ServiceForge. Connect ServiceForge to your AI

COMM message displayed patient safety

COMM message shown in NIBP area indicating communication error

Ranked causes

1. Communication error between NIBP module and monitor circuitry (common)

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

COMM message displayed in MSpO2 area patient safety

Communication error message shown in MSpO2 display area, preventing pulse oximetry reading

Ranked causes

1. SpO2 module or main board defective (common)

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

COMM message displayed in NIBP area patient safety

Communication error message 'COMM' shown in non-invasive blood pressure display area

Ranked causes

1. Communication error between NIBP module and monitor circuitry (rare)

First check

Verify NIBP module and main board communication

Test point: NIBP board-to-main board interface
Expected: Communication link established

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

Communication error in maternal SpO2 module

COMM message shown in MSpO2 area of display

Ranked causes

1. SpO2 module or main board defective (unknown)

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

More symptoms

Dashes displayed in NIBP area
Dashes shown in NIBP display area
ESD precautions during FECG/UA and recorder procedures
ESD precautions for front bezel replacement
Fan replacement
FECG/UA board voltage adjustment
FHR rate and strip chart trend do not correlate
FHR Rate displayed and FHR trend on strip chart paper do not correlate
Front bezel replacement
High blood pressure reading
Main board power supply voltage out of specification
Main power supply replacement
MHR/P pulse source blank when MSpO2 selected
Monitor does not show MSpO2 value - SENSOR message displayed
MOTION message displayed
MOTION message displayed in NIBP area
No monitoring functions and power indicator does not illuminate
No MSpO2 value with SENSOR message
Paper-low photosensor replacement
Paper-out photosensor replacement
Recorder horizontal offset adjustment
Recorder message: PAPER INCORRECTLY LOADED, RELOAD WITH BLACK SQUARES DOWN
Recorder not functioning; incorrect paper loaded message
Recorder paper curls or printing unequal
Recorder paper-loading photosensor replacement required
Recorder prints with vertical offset
Recorder vertical offset adjustment
REPAIR message in maternal SpO2 area
REPAIR message shown in SpO2 area (Nellcor only)
Simulator setup verification
SYSTEM FAULT:ALERT error message displayed
SYSTEM FAULT:DEFAULTS error message displayed
SYSTEM FAULT:DSP error message displayed
SYSTEM FAULT:RAM error message displayed
SYSTEM FAULT:ROM error message displayed
Thermal print head replacement and voltage adjustment
Weak signal on blood pressure measurement

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

Error codes

Code	Meaning	Trigger	Severity
`CHECK CUFF`	Cuff position, connection, or pressure measurement issue preventing accurate reading	System detects improper cuff application, disconnection, or other setup error during measurement	warning
`COMM`	Communication error between built-in NIBP module and main monitor circuitry	NIBP module unable to communicate with monitor during measurement cycle	error
`MOTION`	Excessive patient movement detected during blood pressure measurement	System detects limb movement exceeding acceptable threshold during measurement	warning
`OVERPRESSURE`	Cuff pressure exceeded safe operating limit of 315 mmHg ± 15 mmHg	System detects cuff pressure above over-pressure threshold during measurement attempt	warning
`REPAIR`	NIBP pump failure or system self-test error detected	Pump malfunction or system self-test failure during initialization or measurement	error
`S11.1`	Recorder prints too lightly	Fetal chart prints are barely readable or intermittently light	error
`S7.8`	WEAK SIGNAL message on blood pressure display	Monitor unable to determine blood pressure due to insufficient signal strength	warning
`S8.1`	COMM message in MSpO2 area	Communication error between built-in MSpO2 module and monitor circuitry	error
`S8.2`	Dashes (---) in MSpO2 area	Monitor unable to determine pulse oximetry due to insufficient or erratic signal	warning
`S8.3`	MHR/P pulse source blank when MSpO2 selected	MSpO2 pulse source mode set to Normal instead of Fast	info
`S8.4`	REPAIR message in MSpO2 area (Nellcor only)	System error or self-test failure detected	error
`S8.5`	No MSpO2 value displayed with SENSOR message	Monitor detects wrong sensor type or sensor not recognized	error
`SYSTEM FAULT:ALERT`	Software error detected during initialization	Software exception or fault during startup	error
`SYSTEM FAULT:DEFAULTS`	Default configuration initialization failure	Failure to initialize default parameters on startup	critical
`SYSTEM FAULT:DSP`	DSP board communication or hardware failure	DSP board failure detected during initialization	critical
`SYSTEM FAULT:RAM`	Main board SRAM memory defective	SRAM memory test failure on startup	critical
`SYSTEM FAULT:ROM`	Main board flash memory defective	Flash memory read failure on startup	critical
`SYSTEM FAULT:SOFTWARE`	Software configuration error or incorrect switch setting	Invalid software configuration detected on startup	error
`SYSTEM FAULT:UI KEYPAD`	Communication failure between main board and keypad	Keypad communication bus failure detected	error

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.