Fetal monitors · Avalon Fetal Monitors family

Philips Avalon Fetal Monitor FM20: troubleshooting and error codes

The ServiceForge knowledge base holds 51 documented symptoms for the Philips Avalon Fetal Monitor FM20, with 118 ranked causes, 14 diagnostic checks with test points and expected values, and 0 error codes. Each symptom below shows its causes and the first check; the rest is one connection away. Connect ServiceForge to your AI

Symptoms

INOP Check Paper issued

INOP Check Paper message displayed

Ranked causes

1. Drawer open with paper on sensor (common)
2. Paper jam occurred (occasional)
3. Paper sensor dirty (occasional)
4. Paper sensor defective (rare)
5. Rubber roller dirty (occasional)
6. Paper not approved by Philips (occasional)
7. Inadequate contrast of paper marks (occasional)

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

Display is blank or brightness reduced

No image visible on display or display appears very dim

Ranked causes

1. Display Adapter Board cable not connected (common)
2. Backlight tubes defective (occasional)
3. Back-light inverter defective (occasional)
4. Display adapter board defective (occasional)
5. LCD flat panel defective (occasional)
6. Main CPU Board defective (rare)

First check

Verify Display Adapter cable connection

Test point: Cable between Display assembly and Recorder Adapter Board
Expected: Cable properly connected

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

External device not receiving data

Data is not being transmitted to an external device connected via MIB/RS232 or USB port

Ranked causes

1. MIB/RS232 port not configured for data export (common)
2. Wrong data export protocol driver configured (common)
3. Cable not connected correctly or defective (common)
5. Terminal concentrator does not support dynamic speed negotiation (rare)
6. MIB/RS232 board in wrong slot (occasional)
7. MIB/RS232 board or connector board defective (occasional)

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

No paper transport

Paper does not advance through recorder

Ranked causes

1. Poor internal connection (occasional)
2. Paper jam occurred (occasional)
3. Motor cable disconnected (occasional)
4. Motor defective (rare)
5. Drawer is open (common)

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

Touchscreen not functioning

Touchscreen does not respond to touch input or is disabled

Ranked causes

1. Touchscreen functionality temporarily disabled (common)
2. Touch screen cable not connected (common)
3. Touch controller defective (occasional)
4. Touch sensor defective (occasional)
5. Main CPU Board defective (rare)

First check

Check for padlock symbol on Main Setup key

Test point: Main Setup button display
Expected: No padlock symbol

4 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 and transducer does not work, with or without INOP Bus Master Malfunc message

Ranked causes

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

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

Unit does not power on

Green power LED does not light, no test tone heard from speaker

Ranked causes

1. No AC mains connection (common)
2. Power supply defective (occasional)
3. Power On/Off switch defective (occasional)
4. Software configuration interrupted (rare)
5. Main CPU Board defective (rare)

First check

Verify power cord connection

Test point: Power cord and AC mains socket
Expected: Power cord plugged in and undamaged

1 more check 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 not functioning

Ranked causes

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

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 key missing from screen display, INOP FetRec Equip Malf message shown

Ranked causes

1. Recorder not calibrated (common)
2. EEPROM on Recorder Adapter Board defective (rare)
3. Recorder Controller on Main CPU 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 not out

Paper empty warning displayed at bottom of screen though paper is loaded

Ranked causes

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

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

Alarm occurs but no alarm sound issued patient safety

Alarm triggered but no audio output

Ranked causes

1. Volume set to 0 (common)
2. Speaker defective (occasional)
3. Sound amplifier on Main CPU Board defective (rare)

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

Monitor alarm does not activate Nurse Call patient safety

Monitor generates an alarm but Nurse Call system is not activated

Ranked causes

1. Incorrect configuration present (Relay latency, Relay trigger) (common)
2. Cable connection defective to monitor or nurse call system (common)
3. Flexible Nurse Call Relay I/O board is defective (occasional)

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

No test sound issued

Speaker does not produce test tone during boot or INOP Speaker Malfunct message appears

Ranked causes

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

First check

Verify speaker cable connections

Test point: Speaker cable connections
Expected: Cables properly connected

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

Paper remains blank during normal recorder operation

Recorder running normally but paper output is blank

Ranked causes

1. Thermal Printhead disconnected (occasional)
2. Thermal Printhead defective (occasional)
3. Paper loaded wrong side up (common)

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

Parameter INOP displayed patient safety

Equipment malfunction message displayed for transducer, sensor, patient module, or board (FHR1/2/3, DFHR1/2/3, MECG, Toco, IUP, NBP, FetRec, SpO2, Bus Master)

Ranked causes

1. Transducer, sensor, patient module, or board connection issue (common)
2. Bus master firmware incompatible with software (occasional)
3. Bus master board defective (occasional)

First check

Swap component with known good replacement

Test point: Parameter measurement after swap
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

Poor print quality

Printout has poor or unclear quality

Ranked causes

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

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

Settings Malfunct INOP

Settings malfunction INOP message displayed

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

Speaker Malfunct INOP

Speaker Malfunct INOP message displayed

Ranked causes

1. Speaker cable disconnected (common)
2. Speaker defective (occasional)
3. Sound amplifier on Main CPU Board defective (rare)

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

Transducer connected with Bus Master Malfunc message

Transducer is connected but INOP Bus Master Malfunc message is displayed continuously

Ranked causes

1. Main CPU board is defective (occasional)
2. Transducer is defective (common)
3. Interrupted transducer upgrade or software malfunction (occasional)

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

Green LED blinks continuously

Green power LED blinks indicating cyclic reboots; monitor does not complete boot phase

Ranked causes

1. Hardware failure (common)
2. Software fault (occasional)

First check

Connect Support Tool and search for defective devices

Test point: Monitor connection via crossover cable
Expected: Device detected by Support Tool

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

Monitor temperature too high caution

Check Monitor Temp INOP message displayed

Ranked causes

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

First check

Verify ambient operating environment

Test point: Room temperature and ventilation
Expected: Within manufacturer operating specifications

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

Monitor voltage abnormal caution

Check Monitor Func INOP message displayed indicating problem with voltages

Ranked causes

1. Defective I/O board (common)
2. Main Board defective (occasional)

First check

Remove and reseat I/O boards one at a time

Test point: Each I/O board slot
Expected: INOP clears when defective board identified

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

No video on remote display

Connected remote display is not showing any video output

Ranked causes

1. Video cable is 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

None of the connected USB devices are functioning

Multiple USB-connected devices attached to the monitor are not working

Ranked causes

1. USB port in monitor is defective (occasional)
2. Invalid combination of connected devices or devices are defective (common)

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

Paper not feeding properly

Paper does not advance correctly through recorder

Ranked causes

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

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

Trace not printed correctly with reference to paper gridlines

Printed trace misaligned with paper grid reference lines

Ranked causes

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

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

Tympanic Thermometer does not function

Tympanic Thermometer is not working or displaying data

Ranked causes

1. No connection between base station and thermometer, or base station and monitor (common)
2. Thermometer is defective (occasional)

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

All transducers do not work with Bus Master Malfunc message

All transducers (US, Toco, IUP, ECG) are not functioning and INOP Bus Master Malfunc is displayed

Ranked causes

1. Bus Master Board is defective (common)

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

Bad or distorted printout within first 1 cm of trace

Poor print quality at beginning of recording, first 1 cm distorted

Ranked causes

1. Paper drawer not fully closed before recording (common)

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

Batt Empty INOP patient safety

Batt Empty INOP tone, battery LED flashes, alarms cannot be paused or switched off

Ranked causes

1. Estimated remaining battery time ≤10 minutes (common)

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

Batt Incompat INOP

Batt Incompat INOP tone, incorrect battery installed

Ranked causes

1. Incorrect battery type installed (common)

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

Batt Low INOP

Batt Low INOP tone, battery-powered operating time remaining less than 20 minutes

Ranked causes

1. Battery charge low (common)

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

Battery Malfunct INOP patient safety

Battery Malfunct INOP tone, battery LED flashes, alarms cannot be paused or switched off if not connected to AC power

Ranked causes

1. Monitor cannot determine battery status or communication problem between battery and battery board (occasional)

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

Battery symbol not displayed

Battery symbol missing from display

Ranked causes

1. Monitor not configured for battery operation (common)

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

Charger Malfunct INOP

Charger Malfunct INOP tone, battery LED may flash, problem with battery charger in monitor

Ranked causes

1. Problem with battery charger in monitor (occasional)

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

Check Batt Temp INOP caution

Check Batt Temp INOP tone, battery temperature too high

Ranked causes

1. Battery temperature too high (occasional)

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

FHR transducer cannot be identified patient safety

When multiple ultrasound transducers are attached, cannot determine which FHR transducer is producing INOP using Finder LED

Ranked causes

1. Transducer Finder LED defect (occasional)

First check

Activate Finder LED on suspected transducer

Test point: Touchscreen parameter selection; transducer light output
Expected: Finder LED illuminates on correct transducer

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

Green LED lights but does not turn off

Green power LED stays on continuously during normal operation

Ranked causes

1. Main CPU Board defective (common)

First check

Load new software

Test point: Monitor software
Expected: Green LED turns off after boot

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

INOP after software upgrade

INOP message occurs following software upgrade, possible incomplete or unsuccessful upgrade

Ranked causes

1. Incomplete or unsuccessful software upgrade (common)

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

INOP after software upgrade or option change with NST Report

INOP displayed after software upgrade or option change, monitor settings need updating for NST Report feature

Ranked causes

1. NST Report settings not configured (common)

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

INOP FetRec Chk Config issued

INOP FetRec Chk Config message displayed

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 occurs during normal operation

INOP message displayed, possible monitor software problem

Ranked causes

1. Monitor software problem (unknown)

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

INOP Printhead Overheat issued caution

INOP Printhead Overheat message displayed, printhead temperature too high

Ranked causes

1. Printhead temperature too high (common)

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

INOP Wrong Paper Scale issued

INOP Wrong Paper Scale message displayed, wrong scale paper loaded

Ranked causes

1. Wrong paper scale loaded (common)

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

Internal.Comm.Malf INOP

Internal communication malfunction INOP message displayed

Ranked causes

1. Main CPU Board defective (unknown)

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

Nurse Call Relay INOP message displayed

Monitor displays 'Check Nurse Call Relay' error message

Ranked causes

1. Flexible Nurse Call Relay I/O board is defective (common)

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

Temperature reading is unusually high patient safety

Thermometer displays an abnormally elevated temperature value

Ranked causes

1. Probe cover is damaged or not attached correctly (common)

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

Temperature reading is unusually low patient safety

Thermometer displays an abnormally low temperature value

Ranked causes

1. Probe, probe cover, or ear canal is obstructed (common)

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

Touch calibration incorrect

Touchscreen position invalid or not calibrated

Ranked causes

1. Touch not calibrated (common)

First check

Perform touch calibration

Test point: Calibration procedure in Service Mode
Expected: Calibration completed successfully

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

Transducer appears not to work with Finder LED briefly lighting

Transducer Finder LED lights briefly but either INOP Bus Master Malfunc is displayed or transducer is not recognized with no parameters displayed

Ranked causes

1. Transducer is defective (common)

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

Transducer belt button is broken or damaged caution

Transducer knob or belt button is mechanically damaged

Ranked causes

1. Mechanical damage to belt button (common)

1 corrective action and part numbers 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.