ZOLL AED 3

Asset Type

Defibrillator

Manufacturer

ZOLL

Model

AED 3

What This Guide Helps With

Troubleshooting failure to deliver an advised shock caused by timing, pad connections, battery condition, shock-button operation, or an internal therapy fault.

Step-by-Step Troubleshooting

1. Ensure Patient Safety First

Do not perform extended troubleshooting while the AED is required for an active resuscitation.

When a shock is advised but not delivered:

• Continue CPR according to the clinical response protocol.
• Obtain another verified AED or manual defibrillator immediately.
• Do not delay resuscitation while repeatedly testing the questionable device.
• Transfer defibrillation capability to the replacement device as soon as possible.

Expected outcome: CPR and defibrillation remain available without relying on an AED with uncertain shock delivery.

Continue Clinical Engineering troubleshooting only after the device has been removed from patient use.

2. Identify the Exact AED 3 Version

Determine whether the device is:

• ZOLL AED 3 or AED 3 BLS: The operator must press the flashing Shock button.
• ZOLL AED 3 Automatic: The device delivers the shock automatically after its audible countdown.

The standard AED 3 Shock button illuminates only after the device is charged and ready.

Expected outcome: The reported behavior is compared with the correct operating sequence for that specific model.

3. Document What Happened During the Event

Record:

• Whether SHOCK ADVISED was announced
• Whether the Shock button illuminated or flashed
• Whether the charge-ready tone sounded
• Whether the button was pressed
• Whether RELEASE SHOCK BUTTON, NO SHOCK DELIVERED, CPR ONLY MODE, or another message occurred
• Whether the device restarted or lost power

A NO SHOCK DELIVERED prompt may indicate that the button was not pressed within the allowed period or that an error prevented delivery.

Expected outcome: Operator timing, accessory problems, and internal failure can be differentiated.

4. Inspect the Shock Button Externally

With the device removed from use:

• Check that the Shock button is not physically stuck, recessed, cracked, contaminated, or obstructed.
• Press and release it gently while the AED is off.
• Confirm that it moves freely and returns normally.
• Do not apply liquids, pry around the button, or open the housing.

Expected outcome: The control is externally intact and mechanically free.

If the button is damaged or remains depressed, stop and remove the AED from service.

5. Check for Premature Button Activation

For semi-automatic models, the Shock button must not be held before the AED finishes charging.

If the device announces RELEASE SHOCK BUTTON:

• Release the button completely.
• Wait for the charge-ready tone.
• Confirm that the Shock button begins flashing.
• Press and release the button only when prompted.

ZOLL states that this prompt occurs when the button is pressed before the defibrillator is ready. If the message persists, the AED requires service.

Expected outcome: The AED accepts the button input after reaching the charged-and-ready state.

If this resolves the issue during controlled testing, complete the remaining safety verification before returning the device to service.

6. Inspect the Defibrillation Pads and Connector

Check that:

• The pads cable is fully seated in the AED connector.
• The connector, cable, and strain relief are undamaged.
• The pads are compatible with the AED 3.
• The package is sealed and within its expiration date.
• There is no evidence of moisture, crushing, puncture, or damaged contacts.

The AED may issue prompts such as PLUG IN PADS CABLE, CHECK PADS, ATTACH CORRECT DEFIB PADS, or REPLACE PADS when the connection or pads are unsuitable.

Expected outcome: A known-good, compatible pad set is connected securely.

Replace questionable or expired pads. If replacing the pads resolves the issue, stop troubleshooting and complete functional verification.

7. Check Battery Condition

Inspect the battery compartment and verify:

• The battery is fully seated.
• The battery and compartment contacts are clean, dry, and undamaged.
• No CHANGE BATTERY or low-battery warning is present.
• The battery is within its installation and service-life requirements.

Replace the battery with an approved, known-good battery when its condition is uncertain or when instructed by the AED.

Expected outcome: The AED powers on normally without battery warnings, resets, or interruption during charging.

If the battery replacement resolves the problem, continue with a complete simulator-based discharge test.

8. Run the AED Self-Test

With compatible pads or an approved test load connected:

• Turn the AED off.
• Press and hold the On/Off button for at least five seconds to initiate the self-test.
• Observe all displayed messages and audible prompts.
• Confirm that the green readiness check appears after a successful test.

A failed or blank readiness indicator means the AED is not ready for use and should remain out of service.

Expected outcome: The device passes its self-test and displays the green readiness indicator.

A passed self-test does not by itself close a reported shock-delivery failure. Therapy delivery must still be verified using appropriate test equipment.

9. Perform a Controlled Shock-Delivery Test

Connect the AED only to an approved defibrillator analyzer or AED simulator capable of presenting a shockable rhythm and accepting a discharge.

Verify that the device:

• Recognizes the simulated shockable rhythm.
• Announces SHOCK ADVISED.
• Charges normally.
• Produces the charge-ready tone.
• Illuminates or flashes the Shock button on semi-automatic models.
• Delivers the shock when the button is pressed correctly.
• Registers the delivered shock on the analyzer.
• Announces SHOCK DELIVERED and proceeds to CPR guidance.

ZOLL’s maintenance test requires confirmation of the charge-ready tone, illuminated Shock button, analyzer-recorded discharge, shock count, and subsequent CPR prompt.

Expected outcome: The analyzer confirms successful therapy delivery and acceptable energy output.

If the AED charges but does not discharge when the button is pressed correctly, stop testing and remove it from service.

10. Repeat the Test to Check for Intermittent Failure

When the initial controlled test passes:

• Repeat several analysis-and-discharge cycles according to facility procedure.
• Watch for delayed charging, intermittent button response, resets, unusual sounds, or inconsistent analyzer readings.
• Gently inspect the external pad cable connection without stressing or flexing the connector excessively.

Expected outcome: Shock delivery remains consistent throughout repeated controlled testing.

An intermittent failure should be treated as a confirmed malfunction even when later attempts pass.

If the Problem Persists

When compatible pads, proper operator timing, battery condition, connections, and controlled testing have been addressed, the common external causes have been ruled out.

ZOLL directs removal from service when no shock is delivered after the Shock button is pressed correctly or when the RELEASE SHOCK BUTTON condition persists.

The device should be:

• Removed from service
• Labeled Out of Service
• Replaced in its assigned clinical area
• Sent for authorized repair or bench evaluation
• Reported to ZOLL Technical Service with the serial number, event description, prompts, and test results

Do not open the AED or attempt internal high-voltage, capacitor, charging-circuit, or button-board repair without authorized service procedures and qualifications.

Knowing when to stop is proper troubleshooting.

Clinical Use Tip

Never test shock delivery on a patient, person, loose pads, or an unapproved load. Use another defibrillator for patient care and perform verification only with an appropriate analyzer or simulator.

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 3 announced “Shock Advised,” but pressing the flashing Shock button did not deliver therapy."

Cause

What was observed during troubleshooting.

Example:
"The AED charged and illuminated the Shock button during analyzer testing, but no discharge was recorded when the button was pressed correctly, indicating an internal shock-delivery failure."

Resolution

What action was taken.

Example:
"Removed the AED from service, labeled it Out of Service, provided a replacement unit, documented the event prompts and analyzer results, and submitted the device for authorized repair."

Helpful Details to Include (If Known)

• Exact model: AED 3, AED 3 Automatic, or AED 3 BLS
• Exact voice and screen prompts
• Shock button illumination or flashing
• Charge-ready tone present
• Pad type, lot number, and expiration date
• Pad connector condition
• Battery condition or replacement
• Green readiness indicator status
• Self-test result
• Analyzer model and simulated rhythm
• Measured delivered energy
• Number of successful or failed attempts
• Unusual sounds, heat, odor, damage, or resets
• Final device status
• Replacement AED provided
• ZOLL service case or return number

Final Thought

A failure to deliver an advised shock is a critical therapy malfunction. Protect the patient first, verify simple external causes logically, test only with approved equipment, and escalate immediately when reliable shock delivery cannot be demonstrated. Complete CCR documentation preserves the event details needed for repair, risk review, and future readiness.

That is successful troubleshooting.