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What This Guide Helps With
Troubleshooting missing, intermittent, or inaccurate CPR feedback caused by incompatible pads, CPR sensor position, pad connections, surface movement, or accessory damage.
Step-by-Step Troubleshooting
1. Ensure Patient Safety First
Do not interrupt clinically indicated CPR to investigate the feedback system during an active resuscitation.
If CPR feedback fails during patient care:
- Continue chest compressions according to the facility’s resuscitation protocol.
- Do not delay rhythm analysis or defibrillation solely because corrective CPR prompts are unavailable.
- Use trained clinical judgment for compression rate, depth, recoil, and hand placement.
- Obtain another verified AED or monitor/defibrillator when overall device performance is uncertain.
Expected outcome: CPR and defibrillation continue without depending on unreliable compression feedback.
Continue Clinical Engineering troubleshooting only after the AED Plus has been removed from active patient use.
2. Confirm the Reported Failure
Determine whether the complaint involves:
- No CPR metronome
- No “Push Harder” prompt
- No “Good Compressions” prompt
- Feedback that starts and stops
- Feedback that does not correspond with compression depth
- CPR feedback absent while all other AED functions appear normal
- Failure to recognize any chest-compression movement
Record the exact prompts, indicator behavior, electrode type, and point in the rescue sequence when the failure occurred.
Expected outcome: The complaint is clearly distinguished from an audio, electrode-recognition, or general device failure.
3. Verify That CPR-D-padz Are Installed
Inspect the connected electrodes and package labeling.
The AED Plus CPR monitoring function requires compatible CPR-D-padz with the compression sensor. Standard electrodes or pediatric Pedi-padz II do not provide adult CPR depth feedback. ZOLL states that the CPR monitoring function is intended for adult patients and is not intended for patients under eight years old.
Confirm that:
- The electrodes are labeled CPR-D-padz.
- The package is unopened and within its expiration date.
- The central CPR sensor assembly is present.
- The pads are intended for the AED Plus.
- No adapter or unsupported electrode configuration is being used.
Expected outcome: A sealed, compatible CPR-D-padz set is available.
If the wrong electrode type caused the complaint, replace it with the correct accessory, verify readiness, document the correction, and stop.
4. Inspect the CPR-D-padz Package and Sensor
Without opening a service-ready pad package unnecessarily, inspect it for:
- Torn, punctured, wet, or partially opened packaging
- Crushing or deformation near the CPR sensor
- Bent or sharply folded electrode wiring
- Loose components inside the package
- Contamination or fluid exposure
- Expired labeling
- Evidence that the pads were previously opened or used
A damaged or expired pad set should not be used for patient care. ZOLL instructs users to apply freshly opened, undamaged electrodes that are within their expiration date.
Expected outcome: The electrode package and CPR sensor appear intact.
If damaged, opened, used, or expired, replace the CPR-D-padz, verify the green readiness indicator, document the accessory failure, and stop.
5. Check the Electrode Connector
Verify that the electrode cable connector is:
- Fully seated in the AED Plus
- Straight and not partially disengaged
- Free of contamination, moisture, or visible damage
- Not being pulled by the way the pads are stored
- Connected before performing the readiness evaluation
Inspect the device-side connector externally for bent contacts, damaged plastic, looseness, or foreign material. Do not insert tools into the connector.
ZOLL recommends keeping the electrode cable connected to the AED Plus and lists cable attachment as a check when the device displays a readiness fault.
Expected outcome: The electrode connection is secure and mechanically stable.
If reseating the connector resolves the problem, complete the functional check, return the AED to service only when readiness is normal, document the repair, and stop.
6. Confirm Correct Sensor Placement During Controlled Testing
Use an approved AED simulator, CPR manikin, and facility-authorized test procedure. Do not test compression feedback on a person.
Confirm that the CPR sensor would be positioned:
- Over the center of the chest
- Between the rescuer’s hands and the patient
- In the orientation shown on the CPR-D-padz graphics
- Flat against the manikin without being tilted or displaced
- On a firm testing surface
The CPR-D-padz sensor reports chest-compression motion to the AED Plus. Incorrect sensor placement or movement outside the compression point can prevent accurate feedback.
Expected outcome: The sensor remains centered and detects controlled compressions.
If repositioning restores consistent feedback, document improper sensor placement as the cause and stop.
7. Check the Test Surface and Manikin
Place the CPR manikin on a firm, stable surface.
Avoid testing on:
- A mattress without an approved backboard
- A soft stretcher surface
- A moving cart
- A flexible tabletop
- A manikin with a damaged or excessively stiff chest mechanism
Confirm that the manikin allows measurable chest displacement and returns fully after each compression.
Expected outcome: Compression movement occurs through the sensor rather than being absorbed by the support surface.
If changing the surface or manikin resolves the issue, repeat the test for consistency, document the test-condition problem, and stop.
8. Observe the CPR Sequence and Prompts
Using the simulator and test manikin, advance the AED through its normal rescue sequence until it instructs the rescuer to begin CPR.
Verify:
- The AED enters the CPR interval.
- The metronome begins when expected.
- Compression-related prompts respond to changes in depth.
- Feedback remains consistent during repeated compressions.
- Other voice and visual prompts remain normal.
The AED Plus CPR monitoring function provides a metronome and voice or visual feedback intended to encourage appropriate adult compression rate and depth.
Expected outcome: The metronome and corrective prompts operate during the CPR phase.
If the device has not entered a CPR interval, absent feedback may be normal rather than a failure.
9. Compare With a Known-Good CPR-D-padz Test Accessory
When permitted by the facility and ZOLL service procedures, repeat the controlled test using a known-good, compatible CPR-D-padz test accessory or approved training interface.
Do not open a patient-use electrode package merely for troubleshooting unless it will be removed from inventory afterward.
Interpret the results:
- Known-good accessory works: The original CPR-D-padz or sensor is defective.
- Both accessories fail: The AED connector, processing, audio, or internal CPR detection circuit may be defective.
- Feedback is intermittent when the connector moves: Suspect connector or cable damage.
Expected outcome: The failure is isolated to either the electrode assembly or the AED.
If replacing the accessory resolves the issue, complete the readiness check, document the result, and stop.
10. Check Battery and Readiness Status
Inspect the AED Plus status indicator.
Do not return the AED to service if:
- A red “X” is displayed
- The device is beeping while turned off
- A “Change Batteries” prompt occurs
- A “Unit Failed” message is heard
- The device fails its manual self-test
ZOLL instructs that a unit displaying a red “X” or emitting a warning beep should not be placed in service.
If battery replacement is indicated, replace all ten batteries as a complete matched set using the manufacturer-specified type and follow the approved battery-reset procedure.
Expected outcome: The AED completes its self-test and shows the green check readiness symbol.
If normal readiness and CPR feedback return, document the battery or readiness condition and stop.
11. Perform a Final Functional Verification
After correcting any accessory, connection, or battery issue:
- Connect a compatible electrode test accessory.
- Power on the AED.
- Confirm the expected “Unit OK” and pad-recognition prompts.
- Complete the approved simulated rescue sequence.
- Verify CPR metronome and compression feedback.
- Power off the unit.
- Wait for the post-test sequence to complete.
- Confirm the green check appears and no warning beep is present.
ZOLL’s checkout procedure requires successful startup, correct pad recognition, and a green readiness indicator before the AED is placed into service.
Expected outcome: CPR feedback functions consistently and the AED returns to normal ready status.
If the Problem Persists
If compatible CPR-D-padz, connector seating, sensor placement, test conditions, battery condition, and readiness checks are satisfactory but compression feedback remains absent or inaccurate, common external causes have been ruled out.
The problem may involve the electrode connector, compression-detection circuitry, audio system, or internal processing.
The device should be:
- Removed from service
- Labeled Out of Service
- Replaced with another verified AED
- Sent for authorized repair or bench evaluation
Do not open or internally disassemble the AED Plus. ZOLL warns that internal disassembly presents a shock hazard and directs servicing to qualified personnel.
Knowing when to stop and escalate is proper troubleshooting.
Clinical Use Tip
Do not troubleshoot CPR feedback on an active patient. Continue CPR using trained clinical judgment, obtain another verified defibrillator when needed, and evaluate the affected AED only after patient care has been transferred safely.
Work Order Documentation (CCR Method)
CCR = Complaint, Cause, Resolution
Complaint
What was reported by the clinical staff.
Example:
"Clinical staff reported that the ZOLL AED Plus did not provide “Push Harder” or “Good Compressions” feedback during CPR."
Cause
What was observed during troubleshooting.
Example:
"Inspection found that standard adult defibrillation pads without the CPR compression sensor were connected instead of CPR-D-padz."
Resolution
What action was taken.
Example:
"Installed compatible, in-date CPR-D-padz, completed a simulated rescue and compression-feedback test, and confirmed a green readiness indicator before returning the AED to service."
Helpful Details to Include (If Known)
- Patient use or controlled test
- CPR-D-padz part and expiration information
- Electrode package condition
- Connector inspected and reseated
- Exact voice or display prompts
- Metronome operation
- CPR sensor position
- Test manikin and surface used
- Known-good accessory comparison
- Battery condition
- Green check or red “X” status
- Manual self-test result
- Environmental factors or surface movement
- Indicator lights and readiness status
- Final device status
- Removed-from-service or returned-to-service decision
Final Thought
Reliable CPR feedback depends on the correct electrode assembly, proper sensor placement, stable test conditions, secure connections, and normal AED readiness. Patient safety comes first, followed by logical external checks, appropriate escalation, and complete CCR documentation.
That is successful troubleshooting.