Fetal monitors · Avalon family

Philips Avalon FM40/FM50: troubleshooting and error codes

The ServiceForge knowledge base holds 44 documented symptoms for the Philips Avalon FM40/FM50, with 106 ranked causes, 29 diagnostic checks with test points and expected values, and 27 error codes. Each symptom below shows its causes and the first check; the rest is one connection away. Connect ServiceForge to your AI

Symptoms

External device not receiving data

LAN/RS232 connected device (e.g., OB TraceVue surveillance system) does not receive data from monitor

Ranked causes

1. LAN/RS232 port not configured for data export (common)
2. Cable not connected correctly or defective (common)
3. External device does not support data export protocol version (occasional)
4. Terminal concentrator does not support dynamic speed negotiation (occasional)
5. LAN/RS232 board in wrong slot (occasional)
6. LAN/RS232 board defective (rare)
7. Wrong cable used for RS232 (occasional)

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

Display is blank or brightness reduced

Screen shows no image or very dim display

Ranked causes

1. Display flex cable not connected properly (common)
2. Backlight inverter cable not connected properly (common)
3. Backlight tubes defective (occasional)
4. Backlight inverter defective (occasional)
5. LCD flat panel defective (rare)
6. API Board defective (rare)

First check

Inspect display flex cable

Test point: Display assembly to API Board connection
Expected: Firmly connected at both ends

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

INOP CHECK PAPER message issued

Check paper error message displayed on recorder or console

Ranked causes

1. Drawer open with paper on sensor (common)
2. Paper jam (common)
3. Paper sensor dirty (occasional)
4. Paper sensor defective (occasional)
5. Rubber roller slipping (occasional)
6. Non-approved paper being used (common)

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

Green LED does not light up

No power indication and no test tone heard from speaker

Ranked causes

1. No AC mains connection (common)
2. Power supply defective (occasional)
3. Switch board cable disconnected (common)
4. Switch board defective (occasional)
5. API Board defective (occasional)

First check

Verify AC power cord connection

Test point: Power cord connector
Expected: Firmly seated in AC outlet

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

Transducer Finder LED does not light after plugging in

Transducer Finder LED does not illuminate after insertion, transducer appears not to work, INOP BUS MASTER MALFUNC may display

Ranked causes

1. Defective transducer cable (common)
2. Defective connector block (common)
3. Transducer or connector block is defective (occasional)
4. API Board is defective (occasional)
5. No power to API Board (rare)

First check

Visually inspect transducer cable connector

Test point: transducer cable connector
Expected: no damage visible

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

Keyboard/Mouse not functioning

Keyboard or mouse attached directly to monitor does not respond

Ranked causes

1. Keyboard/Mouse not connected properly (common)
2. Keyboard/Mouse defective (occasional)
3. PS/2 I/O board not properly plugged in (occasional)
4. PS/2 I/O board defective (rare)

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

No paper transport in recorder

Fetal recorder paper does not advance during operation

Ranked causes

1. Drawer is open or not properly closed (common)
2. Paper jam (common)
3. Stepper motor cable disconnected (occasional)
4. Stepper motor defective (occasional)

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

No recorder key available and INOP FetRec EQUIP MALF issued

Recorder control key does not appear on screen; equipment malfunction message displayed

Ranked causes

1. Recorder has not been calibrated (common)
2. EEPROM on API Board defective (rare)
3. Recorder Controller on API Board defective (rare)
4. Recorder cable disconnected (occasional)

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

Paper empty warning issued but paper is not depleted

Fetal recorder paper empty warning displayed in status line while paper remains in drawer

Ranked causes

1. Drawer is open (common)
2. Paper jam (common)
3. Paper sensor disconnected (occasional)
4. Paper sensor defective (occasional)

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

Speaker malfunction

INOP message 'Speaker Malfunct.' is displayed; alarm occurs but no sound is issued

Ranked causes

1. Speaker cable disconnected (common)
2. Speaker defective (common)
3. Sound amplifier on API Board defective (occasional)
4. Volume set to 0 (common)

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

Touchscreen not functioning

Screen does not respond to touch input

Ranked causes

1. Touchscreen functionality disabled (common)
2. Touchscreen cable not connected (occasional)
3. Touch controller defective (occasional)
4. Touch Sensor defective (occasional)

First check

Check for padlock symbol on Main Screen

Test point: Main Screen key
Expected: No padlock icon visible

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

Individual Parameter INOP patient safety

Single parameter shows INOP (FHR, NBP, SpO2, TOCO, etc) indicating component malfunction

Ranked causes

1. Transducer, sensor, patient module or board defective (common)
2. Bus master firmware incompatible after software upgrade (occasional)
3. API Board defective (occasional)

First check

Swap suspected component

Test point: Component slot/connector
Expected: INOP disappears and parameter measures normally

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

No test sound or Speaker Malfunction INOP

Speaker does not produce test tone during boot or INOP message displayed

Ranked causes

1. Speaker cable disconnected (common)
2. Speaker defective (occasional)
3. API Board defective (rare)

First check

Inspect speaker cable

Test point: Speaker connectors
Expected: Firmly connected

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

Poor print quality

Fetal recorder printout is of poor quality with missing or faint marks

Ranked causes

1. Heat setting needs adjusting (common)
2. Thermal Printhead dirty (common)
3. Thermal Printhead failure (occasional)

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

Recorder paper remains blank

Fetal recorder appears to operate normally but paper prints no signal or marks

Ranked causes

1. Thermal Printhead disconnected (occasional)
2. Thermal Printhead defective (occasional)
3. Wrong side of paper facing up (common)

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

Remote touch display not responding

Touch screen operation of connected remote display via MIB/RS232 is not possible

Ranked causes

1. Cable not properly connected (common)
2. MIB/RS232 port not configured (common)
3. Factory Defaults were loaded (occasional)

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

Settings malfunction

INOP message indicating problem during configuration cloning process or corrupted settings memory

Ranked causes

1. Problem during cloning process (occasional)
2. Memory space for settings corrupted (occasional)
3. Main CPU Board defective (rare)

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

Check Monitor Temperature INOP caution

INOP message indicates internal temperature exceeds safe operating limit

Ranked causes

1. Environment temperature too high (common)
2. Main Board defective (occasional)

First check

Verify operating environment temperature

Test point: Monitor location
Expected: Within manufacturer specifications

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

Check Settings INOP

INOP occurs during normal operation indicating possible software problem or settings corruption

Ranked causes

1. Monitor software problem (occasional)
2. Incomplete or unsuccessful software upgrade (occasional)

First check

Verify monitor and patient settings

Test point: Configuration Mode
Expected: Settings consistent with expected values

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

Green LED does not blink after power On/Off

Power switch activated but green LED remains unresponsive

Ranked causes

1. Switch board defective (common)
2. Defective processor on API Board (occasional)

First check

Activate power On/Off switch

Test point: Green LED
Expected: LED blinks during boot

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

INOP BUS MASTER MALFUNC displayed, transducer Finder LED lights briefly

Transducer appears not to work; Finder LED lights briefly after plugging in transducer but INOP BUS MASTER MALFUNC message appears or no parameters displayed on screen

Ranked causes

1. Transducer is defective (common)
2. API Board is defective (occasional)

First check

Observe Finder LED and system messages after plugging in transducer

Test point: transducer connector
Expected: Finder LED lights briefly and parameters appear on screen

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

No video on remote display

Remote display connected via MIB/RS232 interface shows no video output

Ranked causes

1. Video cable not properly connected (common)
2. Remote display has no power (common)

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

Paper not feeding properly

Fetal recorder paper advance is sluggish or does not move smoothly

Ranked causes

1. Paper incorrectly loaded (common)
2. Rubber roller dirty (common)

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

Trace not aligned with gridlines

Fetal recorder output trace is offset from paper gridlines

Ranked causes

1. Offset needs adjusting (common)
2. Wrong paper scale being used (common)

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

Unknown transducer connected message displayed

Monitor displays 'Unknown transducer connected' message at bottom of screen, either after software upgrade or without upgrade

Ranked causes

1. Transducer in boot mode after software upgrade (common)
2. Transducer is defective (occasional)

First check

Check if message appeared after software upgrade

Test point: transducer history
Expected: message appeared after upgrade = boot mode issue

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

All transducers not working

US, Toco, IUP and ECG transducers all non-functional, INOP BUS MASTER MALFUNC displayed

Ranked causes

1. API Board is defective (common)

First check

Test multiple transducers in different sockets

Test point: all transducer sockets
Expected: at least one transducer lights Finder LED

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

API Board LED off

LED indicator on API Board is not illuminated

Ranked causes

1. Power supply issue (common)

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

API Board LED on steadily

LED indicator on API Board is lit continuously rather than blinking

Ranked causes

1. API Board malfunction (common)

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

Bad or distorted printout within first 1 cm

Fetal recorder output shows distorted or poor quality marks at start of trace

Ranked causes

1. Paper drawer not fully closed (common)

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

Calibration: Fetal recorder maintenance

Preventive maintenance of recorder platen, thermal printhead and paper sensor to maintain print quality

Ranked causes

1. Scheduled preventive maintenance (common)

First check

Inspect recorder platen, thermal printhead and paper sensor

Test point: Fetal recorder assembly
Expected: No visible dust or debris; printhead clean and functional

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

Calibration: Noninvasive blood pressure measurement patient safety

Performance test for noninvasive blood pressure measurement system per service requirements

Ranked causes

1. Scheduled preventive maintenance (common)

First check

Perform full performance testing of blood pressure parameter

Test point: Noninvasive blood pressure measurement system
Expected: Per patient simulator or specified tools test results

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

Calibration: Protective earth leakage current high voltage

Measurement and verification of protective earth leakage current in multiple socket outlet configuration

Ranked causes

1. Scheduled safety compliance test (common)

First check

Measure protective earth leakage current with all components connected and powered

Test point: Multiple portable socket outlet system
Expected: Sys3 <= 100μA, <= 100

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

Calibration: Transducer belt button replacement caution

Replace belt button on Philips Avalon FM40/FM50 fetal monitor transducer. Procedure uses supplied tool to remove old button and install new one with controlled torque application.

Ranked causes

1. Belt button broken or requires replacement (unknown)

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

Calibration: Transducer cable replacement caution

Exchange transducer cable on Philips Avalon FM40/FM50 fetal monitor. Procedure involves removing screw covers, top cover, disconnecting old cable and fitting new one with gasket replacement.

Ranked causes

1. Transducer cable requires replacement (unknown)

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

Check Internal Voltage INOP

INOP message indicates voltage problem in monitor

Ranked causes

1. Problem with 5V voltages in monitor (unknown)

First check

Remove and test I/O boards sequentially

Test point: Monitor startup
Expected: System operates without voltage INOP

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

Check TI Config INOP

INOP occurs after software upgrade or option change, NST Report settings require update

Ranked causes

1. NST Report settings not configured for software feature (common)

First check

Verify Setup NST Report Guideline setting

Test point: Setup menu
Expected: Guideline not set to 'none'

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

Cyclic reboot loop

Monitor attempts boot, power fails, LED blinks, display briefly appears then goes dark, cycle repeats

Ranked causes

1. Hardware failure from short circuit, likely NBP board defect (common)

First check

Observe boot sequence behavior

Test point: Green LED and display
Expected: Continuous boot cycle without failure

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

Inadequate contrast or no paper marks on printout

Fetal recorder output shows poor contrast or missing marks on paper

Ranked causes

1. Non-approved paper being used (common)

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

INOP FetRec CHK CONF message issued

Recorder configuration error indicated; recorder speed or scale type not configured

Ranked causes

1. Recorder Speed and/or Scale Type not configured (common)

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

INOP PRINTHEAD OVERHEAT message issued caution

Thermal printhead temperature exceeds safe operating limit

Ranked causes

1. Printhead too hot (common)

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

INOP WRONG PAPER SCALE message issued

Wrong paper scale loaded; international scale loaded instead of US scale or vice versa

Ranked causes

1. Wrong scale paper loaded (common)

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

Internal communication malfunction

INOP message displayed indicating internal communication error on main CPU board

Ranked causes

1. Main CPU Board defective (common)

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

Touch position invalid

Touchscreen responds but cursor position does not match point of contact

Ranked causes

1. Touch calibration problem (common)

First check

Measure touch offset

Test point: Cursor position vs contact point
Expected: Offset <= 5 mm

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

Transducer belt button broken or damaged patient safety

Transducer belt button or knob is broken, cracked or mechanically damaged

Ranked causes

1. Mechanical damage to belt button (common)

First check

Visually inspect belt button and knob

Test point: belt button assembly
Expected: no cracks, breaks or damage visible

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

Error codes

Code	Meaning	Trigger	Severity
`BUS MASTER MALFUNC`	Bus master section of API Board malfunction	Bus master firmware incompatible or API Board defective after software upgrade	error
`CheckInternVoltage`	Internal voltage problem detected	Abnormal 5V or other internal power supply voltage detected during operation	warning
`Check Monitor Func`	Monitor function check required	Internal monitor function test failure	warning
`Check Monitor Temp`	Monitor temperature warning	Internal temperature exceeds safe operating limit	warning
`Check Settings`	Monitor settings validation failure	Settings corruption during operation or after software upgrade	warning
`Check TI Config`	NST Report configuration issue	NST Report Guideline not configured after software upgrade or option change	info
`DFHR1 EQUIP MALF`	Fetal Heart Rate Channel 1 equipment malfunction	Defective FHR1 transducer, sensor, or associated electronics	error
`DFHR2 EQUIP MALF`	Fetal Heart Rate Channel 2 equipment malfunction	Defective FHR2 transducer, sensor, or associated electronics	error
`DFHR3 EQUIP MALF`	Fetal Heart Rate Channel 3 equipment malfunction	Defective FHR3 transducer, sensor, or associated electronics	error
`FetRec EQUIP MALF`	Fetal Recorder equipment malfunction	Defective fetal recorder or associated electronics	error
`FHR1 EQUIP MALF`	Fetal Heart Rate Channel 1 equipment malfunction	Defective FHR1 transducer or associated electronics	error
`FHR2 EQUIP MALF`	Fetal Heart Rate Channel 2 equipment malfunction	Defective FHR2 transducer or associated electronics	error
`FHR3 EQUIP MALF`	Fetal Heart Rate Channel 3 equipment malfunction	Defective FHR3 transducer or associated electronics	error
`INOP CHECK PAPER`	Check paper error on fetal recorder	Paper sensing error detected	warning
`INOP FetRec CHK CONF`	Fetal recorder configuration check error	Recorder speed or scale type not configured	warning
`INOP FetRec EQUIP MALF`	Fetal recorder equipment malfunction	Recorder not calibrated or controller hardware failure	error
`INOP PRINTHEAD OVERHEAT`	Thermal printhead overheating	Thermal printhead temperature exceeds safe limit	warning
`INOP WRONG PAPER SCALE`	Wrong paper scale loaded in recorder	Paper scale does not match configuration setting	warning
`Internal.Comm.Malf.`	Internal communication malfunction	Main CPU Board communication error	critical
`IUP EQUIP MALF`	Intrauterine Pressure equipment malfunction	Defective IUP sensor or associated electronics	error
`MECG EQUIP MALF`	Maternal ECG equipment malfunction	Defective maternal ECG sensor or associated electronics	error
`NBP EQUIP MALF`	Non-invasive Blood Pressure equipment malfunction	Defective NBP sensor or associated electronics	error
`Settings Malfunc.`	Settings malfunction	Configuration cloning error or corrupted settings memory	error
`Speaker Malfunct.`	Speaker malfunction	Speaker cable disconnected, speaker defective, or sound amplifier failure	warning
`SpO2 EQUIP MALF`	Oxygen saturation equipment malfunction	Defective SpO2 sensor or associated electronics	error
`SpO2 SENSOR MALF`	Oxygen saturation sensor malfunction	Defective SpO2 sensor	error
`TOCO EQUIP MALF`	Tocography equipment malfunction	Defective TOCO sensor or associated electronics	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.