Ventilators

Impact Instrumentation Ventilator accessory: troubleshooting and error codes

The ServiceForge knowledge base holds 331 documented symptoms for the Impact Instrumentation Ventilator accessory, with 349 ranked causes, 702 diagnostic checks with test points and expected values, and 63 error codes. Each symptom below shows its causes and the first check; the rest is one connection away. Connect ServiceForge to your AI

Symptoms

Calibration: Mode control and CAL mode operation

Testing MODE control switch positions (OFF, A/C, SIMV, CPAP, CAL) and verifying unit response, LCD display, and calibration completion.

Ranked causes

1. Mode switch not transitioning properly or unit not responding to mode changes (unknown)
2. Calibration abort or incomplete calibration cycle (unknown)
3. Autocal Valve not functioning or pressure baseline incorrect (unknown)

First check

Verify unit powers off

Test point: Unit status indicator
Expected: Unit turns off and is non-operational

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

Alarm LED does not blink during disconnect alarm

Alarm LED fails to blink when disconnect alarm is generated

Ranked causes

1. Disconnect alarm not generated (occasional)
2. Alarm LED circuit failure (occasional)

First check

Generate disconnect alarm condition

Test point: Patient circuit connection
Expected: Disconnect alarm occurs on next breath

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

Alarm LED does not respond to Disconnect alarm

Alarm LED fails to blink when Disconnect alarm is generated

Ranked causes

1. Disconnect alarm not generated (common)
2. Alarm LED circuit malfunction (occasional)

First check

Generate Disconnect alarm condition

Test point: Patient circuit connection
Expected: Alarm LED blinking

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

Alarm LED does not turn solid when mute button pressed

Alarm LED fails to change from blinking to solid state after Mute/Cancel button press during alarm condition

Ranked causes

1. Mute/Cancel button not responding (occasional)
2. Alarm LED control circuit malfunction (occasional)

First check

Press Mute/Cancel button during alarm

Test point: Mute/Cancel push-button
Expected: Button depresses and registers

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

Charge LED does not illuminate

Charge indicator LED fails to light when external power connected and battery disconnected

Ranked causes

1. External power supply not properly connected or insufficient power (common)
2. Charge LED requires warm-up time (occasional)

First check

Verify external power supply connected

Test point: External power input
Expected: Power supply connected and active

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

Comp alarm occurs patient safety

Compressor alarm activates when switching between external air and compressor operation, particularly when external air button is pressed after one external air breath.

Ranked causes

1. Compressor failure to start (common)
2. External gas pressure below minimum (35 PSI) (occasional)

First check

Verify LCD indicator status after pressing External Air button

Test point: LCD display
Expected: OFF

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

Comp alarm occurs during external air to compressor switching patient safety

Compressor alarm is artificially induced when switching between external air and compressor operation; external air valves supply gas during alarm

Ranked causes

1. Compressor fails to start or continues operation abnormally during source switching (unknown)
2. External gas supply below minimum threshold (Failure Code 2) (occasional)

First check

Press External Air button after one external air breath

Test point: LCD indicator
Expected: OFF

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

Comp alarm with external air and compressor switching

Comp alarm occurs during switching between external air and compressor operation, along with possible Vt and Disconnect alarms. External air valves supply gas source during Comp alarm.

Ranked causes

1. Compressor failure or malfunction (unknown)
2. External gas pressure below 35 PSI (common)

First check

Press External Air push-button control after one external air breath

Test point: External Air push-button
Expected: LCD indicator reads OFF

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

Disconnect alarm does not occur on next breath patient safety

Disconnect alarm not triggered when patient circuit is removed from test lung and next breath is fired

Ranked causes

1. Patient circuit not properly disconnected (common)
2. Pressure sensor not detecting lack of airway pressure rise (rare)

First check

Remove patient circuit from test lung

Test point: patient circuit connection
Expected: Circuit disconnected

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

Disconnect alarm does not occur on patient circuit removal patient safety

No alarm triggered when patient circuit is removed from test lung and breath is fired

Ranked causes

1. Pressure sensing circuit not detecting loss of airway pressure (common)
2. Alarm threshold not configured or microcontroller logic failure (occasional)

First check

Remove patient circuit from test lung

Test point: Patient circuit connection
Expected: Circuit disconnected

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

Excessive airway pressure safety shutdown does not occur patient safety

Unit does not shut down when airway pressure exceeds 40 cmH2O for 4 seconds during test

Ranked causes

1. Airway pressure transducer not properly connected or sensing failure (unknown)
2. Safety shutdown threshold not triggered at 40 cmH2O (unknown)

First check

Verify test setup with specified ventilator settings

Test point: Ventilator control panel
Expected: Mode=A/C, Rate=15 BPM, I time=1.0 sec, Vt=500 ml, FIO2=21%

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

External Power Fail alarm does not occur patient safety

No External Power Fail alarm is generated when top fuse is removed in A/C mode with external power and battery connected

Ranked causes

1. Top fuse not removed properly (occasional)
2. Alarm circuit not detecting power loss (rare)

First check

Connect external power and battery

Test point: power connections
Expected: Both connected

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

Failure Code 2 occurs (No Gas, COMP alarm) patient safety

Unit displays Failure Code 2 and COMP alarm after gas supplies are disconnected during test

Ranked causes

1. External air and oxygen supplies disconnected or absent (common)
2. Oxygen supply disconnected or absent (common)

First check

Verify external air supply connected and flowing

Test point: External air inlet
Expected: Air supply connected

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

Failure Code 5 occurs with safety shutdown patient safety

Unit displays Failure Code 5 and triggers 40 cmH2O safety shutdown after 4 seconds of excessive airway pressure

Ranked causes

1. Airway pressure exceeds 40 cmH2O for 4 seconds (common)
2. Transducer disconnection or obstruction during operation (occasional)

First check

Set unit to Mode A/C, Rate 15 BPM, I time 1.0 sec, Vt 500 ml, FIO2 21%

Test point: Unit control panel
Expected: Mode=A/C, Rate=15 BPM, I time=1.0 sec, Vt=500 ml, FIO2=21%

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

LCD screen does not blank during system failure

LCD display remains active instead of blanking when both fuses are removed

Ranked causes

1. Fuses not fully removed or system failure condition not triggered (occasional)
2. LCD control circuit malfunction (occasional)

First check

Verify both fuses removed

Test point: Top and bottom fuse locations
Expected: Both fuses completely removed

1 more check with pass and fail actions are in ServiceForge. Connect ServiceForge to your AI

System Failure LED does not illuminate solid

System Failure LED fails to turn on solid when both top and bottom fuses are removed in A/C mode

Ranked causes

1. Top fuse not removed or external power fail alarm not cleared (occasional)
2. System Failure LED circuit malfunction (occasional)

First check

Connect external power and battery in A/C mode

Test point: Power and mode settings
Expected: Unit in A/C mode with both power sources active

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

Unit does not shut down during system failure patient safety

Unit remains operational instead of shutting down when both fuses are removed

Ranked causes

1. Fuses not both removed or system failure condition not triggered (occasional)
2. Shutdown control circuit malfunction (occasional)

First check

Verify both fuses removed

Test point: Top and bottom fuse locations
Expected: Both fuses completely removed

1 more check with pass and fail actions are in ServiceForge. Connect ServiceForge to your AI

Alarm cancel function does not clear alarm

Pressing Mute/Cancel button does not stop audible alarm or clear alarm message display when external power is disconnected

Ranked causes

1. Cancel button not responding or alarm state not clearing (unknown)

First check

Verify alarm fully cancels after button press

Test point: Mute/Cancel push-button during External Power Fail alarm
Expected: Audible alarm stops; LED turns off; AMC displays no alarm

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

Alarm cancel function not working

Pressing Mute/Cancel button to cancel External Power Fail alarm does not stop audible alarm, turn off LED, or clear message

Ranked causes

1. Mute/Cancel push-button control malfunction or power supply fault (common)

First check

Audible alarm stops when Mute/Cancel pressed during power fail

Test point: Mute/Cancel push-button, speaker output
Expected: Audible alarm stops

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

Alarm cancellation when tidal volume decreased to 500 ml patient safety

Test procedure to verify all alarms cancel when tidal volume is reduced to 500 ml

Ranked causes

1. Tidal volume setting decreased to 500 ml (common)

First check

Decrease Vt setting to 500 ml

Test point: Vt control setting
Expected: 500 ml

1 more check with pass and fail actions are in ServiceForge. Connect ServiceForge to your AI

Alarm does not cancel when Mute/Cancel button pressed during External Power Fail

When Mute/Cancel button is pressed during an External Power Fail alarm, the audible alarm should stop completely and alarm LED should turn off, indicating the alarm has been cancelled rather than muted.

Ranked causes

1. Mute/Cancel button not canceling External Power Fail alarm (unknown)

First check

Audible alarm stops after Mute/Cancel button press

Test point: Mute/Cancel push-button during External Power Fail
Expected: The audible alarm should stop

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

Alarm does not deactivate after clearing disconnect condition patient safety

Alarm remains active or reactivates after disconnect condition is fixed

Ranked causes

1. Disconnect sensor malfunction or circuit not detecting connection restoration (occasional)

First check

Verify disconnect condition is fully restored

Test point: Patient circuit connection
Expected: Circuit securely connected with no gaps

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

Alarm LED and audible reactivate on new alarm condition patient safety

Previously muted alarm LED and audible reactivate when new alarm condition is detected

Ranked causes

1. New alarm condition triggered (common)

First check

Verify alarm reactivation on new condition

Test point: Alarm status indicator
Expected: Alarm LED and audible turn on

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

Alarm LED does not blink on disconnect alarm patient safety

Alarm LED fails to blink when a disconnect alarm is generated

Ranked causes

1. Disconnect condition not properly triggered (common)

First check

Generate Disconnect alarm condition

Test point: patient circuit
Expected: Patient circuit disconnected from test lung

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

Alarm LED does not blink on disconnect condition patient safety

Alarm LED fails to respond to disconnect alarm trigger

Ranked causes

1. Disconnect alarm not properly generated or patient circuit disconnected from test lung (common)

First check

Remove patient circuit from test lung

Test point: Patient circuit connection
Expected: Circuit disconnected

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

Alarm LED does not change state during Mute

Alarm LED fails to transition from blinking to solid during 30-second mute period, or fails to resume blinking after timeout

Ranked causes

1. Alarm LED driver or control circuitry malfunction (unknown)

First check

Observe Alarm LED state before Mute

Test point: Alarm LED indicator
Expected: LED blinking

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

Alarm LED does not come on solid after mute button press

Alarm LED fails to change to solid state when Mute/Cancel push-button is pressed during disconnect alarm

Ranked causes

1. Mute/Cancel button not functioning (occasional)

First check

Press Mute/Cancel push-button

Test point: Mute/Cancel button
Expected: Button responds

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

Alarm LED does not go solid after Mute/Cancel button press

Alarm LED fails to change from blinking to solid state when Mute/Cancel push-button is pressed during active alarm.

Ranked causes

1. Mute/Cancel button malfunction or LED control circuit failure (unknown)

First check

Verify Alarm LED response to Mute/Cancel button press

Test point: Alarm LED indicator
Expected: LED changes from blinking to solid state

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

Alarm LED does not respond correctly

Alarm LED does not transition from blinking to solid during mute or does not turn off during cancel

Ranked causes

1. Alarm LED circuit malfunction or firmware issue (unknown)

First check

Monitor LED state during mute operation

Test point: Alarm LED indicator
Expected: LED transitions from blinking to solid for 30 seconds, then resumes blinking

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

Alarm LED does not transition during Mute period

Alarm LED does not change from blinking to solid on for 30 seconds or does not resume blinking afterwards

Ranked causes

1. LED state machine or control circuit malfunction (unknown)

First check

Alarm LED state when Mute/Cancel pressed during Disconnect alarm

Test point: Alarm LED indicator
Expected: LED transitions from blinking to solid on seconds

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

Alarm LED does not transition from blinking to solid

LED behavior incorrect during mute/cancel operation; should go solid for 30 seconds then resume blinking

Ranked causes

1. Mute/Cancel button not functioning correctly (common)

First check

Verify LED transitions to solid state after Mute/Cancel pressed

Test point: Alarm LED
Expected: Solid on for 30 seconds, then blinking

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

Alarm LED does not turn off after disconnect condition resolved

Alarm LED remains on after patient circuit is reconnected and disconnect alarm is fixed

Ranked causes

1. Pressure sensing not detecting reconnection (occasional)

First check

Reconnect patient circuit and fire breath

Test point: Patient circuit connection and test lung
Expected: Positive airway pressure rise sensed

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

Alarm LED does not turn off after Mute/Cancel pressed

When Mute/Cancel is pressed during External Power Fail alarm, LED remains on instead of turning off

Ranked causes

1. Alarm LED control circuit malfunction (unknown)

First check

Alarm LED status after Mute/Cancel pressed during External Power Fail alarm

Test point: Alarm LED indicator
Expected: LED turns off

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

Alarm Message Center continues displaying alarm during Mute

Alarm Message Center displays alarm message during 30-second mute period when it should remain visible

Ranked causes

1. Mute function affects only audio, not display (expected behavior) (common)

First check

Generate Disconnect alarm and press Mute/Cancel

Test point: Alarm Message Center display
Expected: Alarm message continues displaying during 30-second mute

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

Alarm Message Center displays alarm after Mute/Cancel pressed

AMC screen continues showing alarm after Mute/Cancel button pressed during External Power Fail condition

Ranked causes

1. AMC display logic malfunction (unknown)

First check

Alarm Message Center display after Mute/Cancel pressed

Test point: Alarm Message Center screen
Expected: No alarm displayed

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

Alarm message center does not display during mute patient safety

Alarm Message Center clears or stops showing disconnect alarm during mute period

Ranked causes

1. Display or message logic malfunction (unknown)

First check

Verify alarm message center display during mute

Test point: Alarm Message Center display
Expected: Disconnect alarm still visible while muted

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

Alarm mute duration incorrect caution

Audible alarm does not mute for exactly 30 seconds or LED does not transition as expected

Ranked causes

1. Mute/Cancel button malfunction or timer defect (unknown)

First check

Measure mute duration after Mute/Cancel button press

Test point: Audible alarm output
Expected: Mute for 30 seconds, then resume, ±1 second

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

Alarm mute function not working

Pressing Mute/Cancel button during active alarm does not silence audible alarm or change LED state

Ranked causes

1. Mute/Cancel push-button control malfunction (common)

First check

Audible alarm mutes when Mute/Cancel pressed during active alarm

Test point: Mute/Cancel push-button, speaker output
Expected: Audible alarm silenced for 30 seconds

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

Alarm Mute/Cancel button does not silence alarm caution

Pressing Mute/Cancel button fails to silence alarm LED and audible tone during alarm condition

Ranked causes

1. Mute/Cancel button circuit or alarm driver malfunction (occasional)

First check

Press Mute/Cancel button during alarm condition

Test point: Mute/Cancel push-button control
Expected: Button press registered

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

Alarms cancel after oxygen concentration reduced patient safety

O2 Low/Fail and FIO2 alarms clear when concentration set to 21% despite low tank pressure

Ranked causes

1. Alarm inhibit when FIO2 concentration low (common)

First check

Verify tidal volume maintained on external air/compressor

Test point: Volume delivery
Expected: Tidal volume sustained

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

Alarms cancel after tidal volume decreased to 500 ml patient safety

Both Vt and Vt Settings alarms clear when tidal volume reduced to 500 ml

Ranked causes

1. Tidal volume returned within acceptable range (common)

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

Alarms cancel when oxygen concentration reduced to 21% patient safety

Both O2 Low/Fail and FIO2 alarms clear when oxygen concentration setting is reduced to room air level

Ranked causes

1. Alarm condition resolves at lower oxygen demand (common)

First check

Set oxygen concentration to 21%

Test point: FIO2 control
Expected: 21%

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

Alarms cancel when oxygen concentration set to 21% patient safety

O2 Low/Fail and FIO2 alarms clear when concentration reduced to room air level

Ranked causes

1. Oxygen concentration at non-emergency level (common)

First check

Set oxygen concentration to room air level

Test point: Oxygen concentration control
Expected: 21%

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

Alarms cancel when tidal volume reduced patient safety

All active alarms clear when tidal volume decreased to 500 ml

Ranked causes

1. Tidal volume within acceptable range (common)

First check

Decrease tidal volume setting

Test point: Vt control
Expected: 500 ml

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

Alarms cancel when tidal volume setting decreased patient safety

All active alarms cancel when Vt setting is decreased to 500 ml

Ranked causes

1. Tidal volume setting returned to acceptable range (common)

First check

Verify tidal volume setting

Test point: Vt control
Expected: 500 ml

Alarms cancel when Vt reduced to 500 ml patient safety

All active Vt and Settings alarms are cleared when tidal volume setting is decreased to 500 ml

Ranked causes

1. Tidal volume setting returns to acceptable range (common)

First check

Decrease Vt setting to 500 ml

Test point: Vt control setting
Expected: All alarms cancel

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

Alarms cancel when Vt setting normalized

When tidal volume setting decreased to 500 ml, all active alarms cancel

Ranked causes

1. Vt setting returned to acceptable range (common)

First check

Decrease Vt setting

Test point: Vt control setting
Expected: 500 ml

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

Alarms do not cancel when oxygen concentration returns to safe level patient safety

Alarms should cancel when oxygen concentration is set to 21% after low tank pressure condition

Ranked causes

1. Alarm reset logic malfunction (occasional)

First check

Set oxygen concentration

Test point: O2 concentration control
Expected: 21%

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

AMC does not display EXTERNAL POWER LOW alarm

AMC screen should display EXTERNAL POWER LOW alarm message when external power voltage falls to threshold

Ranked causes

1. Display communication or alarm message circuit failure (occasional)

First check

Visually verify AMC alarm message display

Test point: AMC screen
Expected: EXTERNAL POWER LOW alarm message displayed

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

Audible alarm comes on continuously patient safety

System generates continuous audible alarm during Failure Code 5 testing when airway pressure exceeds 40 cmH2O for 4 seconds

Ranked causes

1. Excessive airway pressure above 40 cmH2O sustained for 4 seconds (common)

First check

Pressurize syringe to raise airway pressure above 40 cmH2O

Test point: Transducer fitting via syringe with hose
Expected: Airway pressure above 40 cmH2O sustained for 4 seconds
Tools: Syringe with hose, pressure transducer

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

Audible alarm does not mute for 30 seconds

Alarm sound continues or does not resume after mute period; should mute when Mute/Cancel pressed and resume after 30 seconds

Ranked causes

1. Mute/Cancel control circuit malfunction (common)

First check

Verify audible alarm mutes when Mute/Cancel pressed

Test point: Alarm speaker
Expected: No audible alarm for 30 seconds

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

Audible alarm does not mute when Mute/Cancel button pressed

When Mute/Cancel push-button is pressed during an active alarm, the audible alarm should silence for 30 seconds before automatically resuming, but it may not mute or resume correctly.

Ranked causes

1. Mute/Cancel button malfunction or not responding (unknown)

First check

Audible alarm mutes after Mute/Cancel button press

Test point: Mute/Cancel push-button
Expected: Audible alarm should mute for 30 seconds

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

Audible alarm does not sound at secondary shutdown caution

Audible alarm should sound continuously when unit shuts down at secondary voltage threshold (9.50V - 10.50V)

Ranked causes

1. Alarm circuit malfunction during secondary shutdown (occasional)

First check

Audibly verify alarm activation

Test point: Audible alarm speaker
Expected: Continuous audible alarm at secondary shutdown

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

Audible alarm does not sound continuously at shutdown

System failure LED comes on but audible alarm fails to sound when unit shuts down due to low voltage

Ranked causes

1. Low battery voltage drops below shutdown threshold (common)

First check

Verify system shuts down within specified voltage range

Test point: External power jack
Expected: 8.5V - 9.3V, 8.5-9.3V

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

Audible alarm does not sound continuously with both fuses removed

Continuous audible alarm tone not generated when both fuses are removed

Ranked causes

1. Both fuses not properly removed (occasional)

First check

Confirm both fuses removed

Test point: fuse positions
Expected: Both top and bottom fuses removed

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

Audible alarm does not sound during low battery shutdown

Continuous audible alarm does not activate when battery voltage drops below shutdown threshold

Ranked causes

1. Audible alarm circuit failure (rare)

First check

Verify audible alarm sounds

Test point: Audible alarm output
Expected: Alarm on continuously

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

Audible alarm does not sound on dual fuse failure patient safety

Continuous tone from audible alarm not heard when both fuses are removed

Ranked causes

1. Top and bottom fuses not both removed or alarm circuit failure (common)

First check

Ensure both fuses removed

Test point: Top and bottom fuse locations
Expected: Both fuses absent

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

Audible alarm does not sound on shutdown caution

Audible alarm should sound continuously when unit shuts down due to low voltage

Ranked causes

1. Alarm circuit malfunction or speaker failure (occasional)

First check

Audibly verify alarm activates

Test point: Audible alarm speaker
Expected: Continuous audible alarm when unit shuts down

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

Audible alarm does not stop after Mute/Cancel pressed

Operator presses Mute/Cancel button but alarm continues sounding instead of stopping

Ranked causes

1. Mute/Cancel button not functioning (unknown)

First check

Audible alarm status after Mute/Cancel pressed during External Power Fail alarm

Test point: Mute/Cancel push-button control
Expected: Audible alarm stops

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

Audible alarm repeating 4 to 5 pulse pattern caution

Ventilator emitting repeating 4 to 5 pulse audible alarm

Ranked causes

1. Unknown alarm condition (unknown)

More symptoms

Backlight does not respond to ambient light
Backlight does not respond to hand proximity sensor
Backup Ventilator flow below minimum
Backup ventilator flow insufficient
Backup ventilator flow rate below specification
Backup ventilator flow rate insufficient
Backup ventilator flow verification
Backup ventilator I time verification
Backup ventilator inspiratory time incorrect
Backup ventilator inspiratory time out of specification
Backup Ventilator manual trigger does not function correctly
Backup ventilator manual trigger not functioning
Backup ventilator PIP relief pressure incorrect
Backup Ventilator PIP relief pressure out of specification
Backup ventilator rate incorrect
Backup ventilator rate out of specification
Backup ventilator rate verification
Battery charger voltage output
Battery fail alarm not functioning
Battery fail condition not functioning
Battery Fail condition test
Battery shutdown voltage out of range
Battery voltage below shutdown threshold
Battery voltage measurement
Battery voltage out of range
Battery voltage out of specification
Battery voltage too low
Calibration abort when Mode switch turned away during CAL mode
Calibration: Airway pressure baseline
Calibration: Autocal valve check
Calibration: Backlight Threshold
Calibration: CAL mode verification
Calibration: External Air OFF LCD indicator
Calibration: Mode control and autocal valve
Calibration: Real Time Clock Reset
Calibration: Tidal volume alarm limits
Calibration: Unit pressure baseline
Cancel button does not stop External Power Fail alarm
Cancel function does not clear External Power Fail alarm
Canceling alarm clears all indicators
Charge LED does not light
Charger output voltage out of range
Charger voltage measurement
Charger voltage out of range
Charger voltage out of specification
Charger voltage output incorrect
Comp alarm does not occur when compressor operation initiated
Comp alarm during compressor operation
Comp alarm occurs during compressor start
Comp alarm occurs during External Air switching
Comp alarm occurs with low external air pressure
Compressor alarm (Comp) occurs
Compressor fails to start
Control breath generation at given settings
Control breath not generated at set parameters
Disconnect alarm does not cancel on circuit reconnection
Disconnect alarm does not cancel when circuit reconnected
Disconnect alarm does not deactivate after fix
Disconnect alarm does not occur on patient circuit disconnection
Disconnect alarm generated
Excessive Negative Pressure alarm (Failure Code 6)
Exhaust Valve Failure alarm (Failure Code 5)
Exhaust valve opens and stays open
Extended Non-Use alarm cannot be verified during final test
External Power Fail alarm does not cancel
External Power Fail alarm does not cancel after mute
External Power Fail alarm does not cancel after Mute/Cancel button press
External power fail alarm does not cancel properly
External Power Fail alarm does not cancel when Mute pressed
External power low alarm
External Power Low alarm does not activate
External Power Low alarm does not occur
External Power Low alarm does not trigger
External Power Low alarm does not trigger at correct voltage
External power low alarm does not trigger at expected voltage
External Power Low alarm does not trigger at threshold
External power low alarm occurs
External power low alarm threshold
External power low alarm threshold incorrect
External power shutdown
External power shutdown threshold
External power shutdown threshold not met
External power shutdown voltage out of range
Failure Code 2 - No Gas COMP alarm
Failure Code 2 (No Gas, COMP) alarm does not occur
Failure Code 2 (No Gas, Comp) alarm during low external gas pressure
Failure Code 2 (No Gas, Comp) alarm generation
Failure Code 2 displayed
Failure Code 2 occurs during gas supply test
Failure Code 3 (Excessive Airway Pressure at startup)
Failure Code 3 (Excessive Airway Pressure) alarm
Failure Code 3 displayed
Failure Code 4 (Memory check failure)
Failure Code 4 (Memory check failure) alarm
Failure Code 4 displayed
Failure Code 5 (Airway pressure exceeds 40 cmH2O for 4 seconds)
Failure Code 5 (Excessive Airway Pressure) safety shutdown does not trigger
Failure Code 5 (Exhaust Valve Failure) alarm
Failure Code 5 (Safety Shutdown - High Airway Pressure) alarm
Failure Code 5 alarm triggered
Failure Code 5 displayed
Failure Code 5 displayed with safety shutdown
Failure Code 5 safety shutdown at high airway pressure
Failure Code 5 triggered
Failure Code 5 triggered with high airway pressure
Failure Code 5 with safety shutdown
Failure Code 5: Excessive airway pressure safety shutdown
Failure Code 5: Exhaust Valve Failure
Failure Code 6 (Excessive Negative Pressure) alarm
Failure Code 6 alarm triggered
Failure Code 6 displayed
Failure Code 6 triggered
Failure Code 6: Excessive Negative Pressure
Failure Code 7 occurs during operation
FIO2 alarm does not occur at low oxygen pressure
FIO2 alarm does not occur at low oxygen tank pressure
FIO2 alarm occurs
FIO2 alarm occurs at low oxygen pressure
FIO2 alarm occurs at low oxygen tank pressure
FIO2 alarm occurs at low tank pressure
Flow in Backup Ventilator test
Gas flow does not stop at 40 cmH2O pressure
Gas flow does not stop at pressure relief threshold
I time in Backup Ventilator test
LCD screen blanks
LCD screen does not blank with both fuses removed
Low battery alarm does not activate at correct threshold
Low battery alarm does not trigger
Low battery alarm does not trigger at correct voltage
Low battery alarm not triggering
Low Battery Alarm occurs
Low Battery Alarm occurs at incorrect voltage
Low battery alarm threshold out of specification
Low Battery Alarm threshold test
Low Battery Alarm triggers
Manual breath beep not heard when button held during inhalation
Manual Breath button does not generate breath
Manual breath button does not produce audible beep
Manual Breath button does not trigger breath
Manual Breath button generates no audible beep
Manual Breath button held during inhalation does not queue breath after cycle
Manual Breath button holds breath when pressed during inhalation
Manual Breath button triggers during inhalation or exhalation
Manual Breath button unresponsive
Manual Breath button unresponsive during inhalation or exhalation
Manual Breath button unresponsive when held during inhalation
Manual Breath control does not generate breath
Manual breath delivery during setup
Manual breath does not generate audible beep
Manual Breath does not generate control breath
Manual breath does not trigger
Manual breath does not trigger during inspiration or expiration
Manual Breath function inactive during inspiration or exhalation
Manual Breath function not triggering
Manual Breath function unresponsive when button held during inhalation
Manual breath hold not functioning
Manual breath not generated
Manual breath not triggered
Manual breath push-button control
Manual breath triggered during inhalation or exhalation hangs or continues indefinitely
Manual trigger does not control gas flow properly
Manual trigger does not deliver gas flow
Manual trigger function verification
Manual trigger gas flow does not respond to pressure buildup
Manual Trigger in Backup Ventilator test
Mode switch to A/C
Mode switch to CAL abort test
Mode switch to CAL with successful calibration
Mode switch to CPAP
Mode switch to OFF
Mode switch to SIMV
Mode switch: A/C mode
Mode switch: CAL mode abort
Mode switch: CAL mode calibration
Mode switch: CPAP mode
Mode switch: OFF mode
Mode switch: SIMV mode
Mute button does not silence alarm for 30 seconds
Mute/Cancel button does not silence alarm message
Mute/Cancel function suppresses alarm audible and LED
Muting alarm for 30 seconds
No Gas alarm (Failure Code 2) does not trigger at low external gas pressure
O2 Low/Fail alarm does not occur at low oxygen tank pressure
O2 Low/Fail alarm does not occur at low tank pressure
O2 Low/Fail alarm occurs
O2 Low/Fail alarm occurs at low oxygen pressure
O2 Low/Fail alarm occurs at low oxygen tank pressure
O2 Low/Fail alarm occurs at low tank pressure
O2 Low/Fail alarm triggers at low tank pressure
PIC Line 1 does not display EXT PWR LOW message
PIP relief does not occur at correct pressure
PIP relief in Backup Ventilator test
PIP relief not occurring at correct pressure
PIP relief pressure verification
Preventative Maintenance alarm cannot be verified during final test
Rate in Backup Ventilator test
Rate, Inspiration Time, Tidal Volume controls non-functional in CPAP mode
System does not shut down at correct external power threshold
System does not shut down at low external power
System does not shut down at secondary threshold with external power low
System fail LED comes on
System Failure LED and alarm activate incorrectly
System failure LED does not activate on shutdown
System failure LED does not come on during shutdown
System Failure LED does not come on solid with both fuses removed
System failure LED does not illuminate at secondary shutdown
System failure LED does not illuminate during low battery
System Failure LED does not illuminate on dual fuse failure
System failure LED does not illuminate on shutdown
System failure LED should come on during shutdown
System Failure LED solid on
System shuts down during external power test
Tidal volume not maintained during low oxygen pressure
Total Flow Backup alarm after compressor inlet occlusion
Total Flow Backup alarm does not occur after compressor occlusion
Total Flow Backup alarm during low compressor inlet flow
Total Flow Backup Alarm not occurring
Total Flow Backup alarm not triggered
Total Flow Backup alarm occurs
Total Flow Backup alarm occurs during compressor inlet occlusion
Total Flow Backup alarm occurs with compressor inlet occlusion
Unit does not shut down after gas supply disconnected
Unit does not shut down at -10 cmH2O airway pressure
Unit does not shut down at +100 cmH2O airway pressure
Unit does not shut down at expected low voltage
Unit does not shut down at expected voltage
Unit does not shut down at External Power Low shutdown threshold
Unit does not shut down at low external power voltage
Unit does not shut down at negative airway pressure
Unit does not shut down at second low voltage threshold
Unit does not shut down on dual fuse failure
Unit does not shut down with both fuses removed
Unit should shut down at excessive negative pressure
Unit should shut down at high airway pressure
Ventilator failure code 2 (No Gas, COMP alarm)
Verify tidal volume maintained after oxygen concentration change to 21%
Verify tidal volume maintained during oxygen pressure low condition
Verify tidal volume maintained when oxygen concentration returned to 60%
Vt alarm cascades with Vt Settings alarm on display
Vt alarm clears at 500 ml setting
Vt alarm displaces Settings alarm on display
Vt alarm does not occur at high tidal volume
Vt alarm does not occur when tidal volume further increased
Vt alarm occurs
Vt alarm occurs above 1150 ml
Vt alarm occurs at 1150 ml
Vt alarm occurs at high tidal volume setting
Vt alarm occurs when setting increased
Vt alarm occurs when tidal volume exceeds 1150 ml
Vt alarm occurs when tidal volume exceeds critical limit
Vt alarm occurs when tidal volume exceeds higher limit
Vt alarm occurs when tidal volume exceeds secondary limit
Vt alarm occurs when tidal volume increased further
Vt alarm replaces Vt Settings alarm
Vt alarm when tidal volume increased to 1150 ml
Vt or Disconnect alarms occur unexpectedly during external air/compressor switching
Vt Settings alarm does not occur
Vt Settings alarm does not occur when tidal volume exceeds limits
Vt Settings alarm does not occur when tidal volume increased
Vt Settings alarm occurs
Vt Settings alarm occurs above 1050 ml
Vt Settings alarm occurs at 1050 ml
Vt Settings alarm occurs at elevated tidal volume
Vt Settings alarm occurs at high tidal volume
Vt Settings alarm occurs at high tidal volume setting
Vt Settings alarm occurs when tidal volume exceeds 1050 ml
Vt Settings alarm occurs when tidal volume exceeds limit
Vt Settings alarm occurs when tidal volume exceeds range
Vt Settings alarm triggered
Vt Settings alarm triggers on parameter change
Vt Settings alarm when tidal volume set above 1000 ml

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

Error codes

Code	Meaning	Trigger	Severity
`5`	Exhaust Valve Failure	Airway pressure reaches +100 cmH2O	error
`6`	Excessive Negative Pressure	Airway pressure drops to -10 cmH2O	error
`7`	Run-Time Transducer Calibration Failure	Transducer calibration fails during operation	error
`Audible alarm`	Continuous audible alarm indicating system shutdown or critical condition	System voltage drops below shutdown threshold (8.5V battery or 9.5V external), or critical fault condition	critical
`Audible Alarm 4-5 pulse`	Repeating audible alarm with 4 to 5 pulse pattern	System failure or alert condition	error
`BATTERY LOW/FAIL`	Battery voltage too low or battery failure detected	Battery voltage drops below 11.1V or battery fails during low power condition	warning
`Calibration Abort Alarm`	Calibration sequence was interrupted or aborted	Mode control switch is moved away from CAL mode before calibration completes	warning
`Calibration Abort Alarm`	Mode switch turned away from CAL mode during calibration	User turns Mode control switch from CAL to another mode before calibration completes	warning
`CHK EXT FUSE`	Check external power fuse	External Power Fail alarm with only top fuse removed and bottom fuse installed	warning
`Comp`	Compressor alarm	External gas supply pressure drops below minimum threshold or compressor fails to start	warning
`Comp`	Compressor failure or inability to provide gas at required pressure	Compressor startup when external air supply is insufficient or compressor malfunction	error
`Comp`	Compressor alarm or failure code related to compressor operation	Compressor fails to start or operate during source switching; external gas supply drops below 35 PSI +/- 2 PSI	warning
`Comp alarm`	Compressor operation alarm during mode transition or startup failure	Compressor attempts to start during external air to compressor switching	warning
`Comp alarm`	Compressor failure or unavailable; gas source switched to external air	Compressor fails to start or external air supply pressure drops below 35 PSI +/- 2 PSI	warning
`Comp alarm`	Compressor alarm - compressor failed to provide gas or pressure backup needed	External air supply depleted or compressor unable to maintain pressure during switch from external air to compressor operation	error
`Comp alarm`	Compressor alarm condition	Compressor activation during external air operation or external gas pressure below 35 PSI ±2 PSI	warning
`Disconnect`	Patient circuit disconnected or no positive airway pressure detected	Patient circuit removed from test lung or pressure rise not sensed after breath is fired	error
`Disconnect Alarm`	Patient circuit disconnected from ventilator outlet	Breath initiated with no positive airway pressure rise sensed	critical
`Extended Non-Use`	Alarm indicating prolonged non-operation of ventilator	Ventilator inactive for extended period	warning
`External Power Fail`	External power supply has been disconnected or is not functioning	Top fuse removed or external power supply disconnected while in A/C mode	warning
`External Power Fail alarm`	External AC power supply lost or disconnected	Disconnection of external power source	warning
`EXTERNAL POWER LOW`	External power supply voltage has dropped below safe operating level	External power voltage drops below 10.5V - 11.1V range	warning
`Failure Code 1`	Self Check failure during startup	Self check fails during system startup	critical
`Failure Code 2`	No Gas, COMP	Gas supplies (external air and oxygen) are disconnected	error
`Failure Code 2`	No gas from compressor during alarm condition	External gas supply pressure drops below 35 PSI +/- 2 PSI while compressor is expected to provide backup	error
`Failure Code 2 (No Gas, Comp)`	No gas supply available to compressor; compressor cannot operate	External gas pressure drops below 35 PSI +/- 2 PSI during compressor operation attempt	critical
`Failure Code 3`	Excessive airway pressure detected during startup	Airway pressure exceeds safe limits at system startup	critical
`Failure Code 4`	Memory check failure alarm	Memory check fails during startup Self Check	critical
`Failure Code 5`	Exhaust Valve Failure	Airway pressure exceeds +100 cmH2O for 2 seconds without unit shutdown	error
`Failure Code 5`	Excessive airway pressure detected - safety shutdown triggered	Airway pressure exceeds 40 cmH2O for 4 consecutive seconds during operation	critical
`Failure Code 5`	Safety shutdown triggered by excessive airway pressure	Airway pressure exceeds 40 cmH2O for 4 seconds or longer	critical
`Failure Code 6`	Excessive Negative Pressure	Airway pressure drops to -10 cmH2O or below for 1.5 seconds without unit shutdown	error
`Failure Code 7`	Run-Time Transducer Calibration Failure	Transducer calibration check fails during operation	error
`FIO2`	Insufficient oxygen flow to achieve requested FIO2 concentration	Oxygen tank pressure below setpoint when FIO2 setting is 60% or higher	warning
`FIO2`	Fractional inspired oxygen out of specification	Oxygen concentration setting and supply pressure mismatch or oxygen delivery failure	critical
`FIO2`	Oxygen concentration cannot be delivered at requested level	Oxygen supply pressure insufficient to meet target FIO2 setting	critical
`FIO2 alarm`	Actual oxygen concentration cannot match the set FIO2 value	Oxygen tank pressure is insufficient to deliver the set oxygen concentration percentage	warning
`FIO2 alarm`	Insufficient oxygen pressure for requested oxygen concentration	Oxygen tank pressure below 45 PSI during high oxygen concentration setting (60%)	error
`LOW (Battery Icon on PIC Line 2)`	Battery voltage low indication on display	Battery voltage drops into low range during operation	warning
`O2 Low/Fail`	Oxygen supply pressure is below acceptable threshold	Oxygen tank pressure drops below 35 PSI +/- 2 PSI	critical
`O2 Low/Fail`	Oxygen supply pressure below threshold	Oxygen tank pressure drops to 35 PSI +/- 2 PSI or below	warning
`O2 Low/Fail alarm`	Oxygen tank pressure is below minimum threshold	Oxygen tank pressure drops below 35 PSI while ventilator is operating	critical
`Preventative Maintenance`	Alarm indicating scheduled maintenance is due	Maintenance interval elapsed or operational hours exceeded	info
`System Failure`	Critical system failure; both external power and internal power sources have failed	Both top and bottom fuses removed simultaneously	critical
`System Failure`	Critical system failure requiring unit shutdown	Both top and bottom fuses removed or both power sources failed	critical
`System Failure`	Multiple system fuses have failed indicating critical system failure	Both top and bottom fuses removed or open circuit	critical
`System failure LED`	System failure detected, LED illuminated continuously	System voltage drops below minimum safe level (8.5V battery or 9.5V external), or critical system fault detected	error
`Total Flow Backup`	Total flow backup alarm during low tidal volume condition	Actual delivered tidal volume drops below 50% of set tidal volume for multiple breaths	warning
`Total Flow Backup`	Actual delivered tidal volume falls significantly below set value	Compressor inlet obstruction or gas flow restriction causes delivered volume to drop below 50% of set value after 4-5 breaths	warning
`Total Flow Backup`	Backup flow alarm due to insufficient delivered tidal volume	Actual tidal volume less than half of set tidal volume for 4-5 breaths	error
`Total Flow Backup Alarm`	Actual tidal volume fell below threshold during backup flow operation	Actual tidal volume drops to less than half of the set tidal volume for 4-5 breaths	warning
`Total Flow Backup Alarm`	Actual delivered tidal volume is significantly less than set value indicating breathing circuit obstruction or compressor failure	Actual tidal volume measured less than half of set tidal volume for 4-5 breaths	warning
`Total Flow Backup alarm`	Total flow backup threshold exceeded	Actual delivered tidal volume falls below 50% of set tidal volume for 4-5 breaths	warning
`Total Flow Backup alarm`	Compressor output flow insufficient; actual tidal volume below minimum threshold	Actual delivered tidal volume falls below half the set tidal volume for 4-5 breath cycles	error
`Vt`	Measured tidal volume exceeds safe operating limit	Tidal volume set to 1150 ml or higher	error
`Vt`	Delivered tidal volume is out of specification	Vt setting increased to 1150 ml; exceeds critical threshold	error
`Vt`	Tidal volume setting significantly exceeds safe maximum limit	Tidal volume setting increased to 1150 ml or higher	error
`Vt alarm`	Measured tidal volume has deviated significantly from set value	Tidal volume setting is increased above approximately 1100 ml or actual delivered volume exceeds limit	error
`Vt Alarm`	Tidal volume out of acceptable range	Delivered tidal volume deviates from set value during normal operation	warning
`Vt alarm`	Tidal volume alarm	Delivered tidal volume deviates from set value	warning
`Vt Settings`	Tidal volume setting outside acceptable operating range	Tidal volume setting increased above approximately 1025 ml	warning
`Vt Settings`	Tidal volume setting has been changed from baseline configuration	Vt changed from 800 ml to 1050 ml or other non-baseline value	warning
`Vt Settings alarm`	Tidal volume setting is outside acceptable operating range	Tidal volume setting is increased above approximately 1000 ml	warning

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.