Stryker LIFEPAK 35

AC power / external power failure

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Asset Type

Defibrillator

Manufacturer

Stryker

Model

LIFEPAK 35

What This Guide Helps With

Troubleshooting loss of AC/external power, missing auxiliary-power indication, failed adapter recognition, or inability to operate and charge from external power.

Step-by-Step Troubleshooting

1. Ensure Patient Safety First

Do not troubleshoot an unresolved external-power fault while the LIFEPAK 35 is supporting an active patient.

If power reliability is questionable, transfer monitoring and therapy readiness to another verified defibrillator before continuing.

Expected: Patient care is not dependent on a device with uncertain power availability.

Why it matters: The LIFEPAK 35 can use a dedicated AC power adapter and a dual-battery system, but an unresolved power-source problem can compromise readiness if available battery capacity is insufficient. Stryker identifies the LIFEPAK 35 AC power adapter as capable of operating the device with or without batteries installed and charging installed batteries.

2. Verify the Reported Failure

Determine exactly what staff observed:

Confirm whether the device still powers on from known-charged LIFEPAK FLEX batteries.

Expected: The complaint is separated into an external-power problem, battery problem, or complete no-power condition.

If the device powers normally from batteries but not from external power, continue with the AC/external-power path.

3. Test the AC Receptacle

Disconnect the LIFEPAK 35 power equipment and verify the wall receptacle using an approved outlet tester or known-good powered device in accordance with facility policy.

Check for:

Whenever possible, test directly from a known-good hospital-grade receptacle.

Expected: Verified AC power is available at the source.

If changing to a known-good outlet resolves the issue, document the faulty source and stop.

4. Inspect the AC Power Cord

Disconnect power and inspect the cord for:

Confirm the cord is fully seated at both the AC source and power-adapter input.

Stryker lists a dedicated North American hospital-grade AC power cord among LIFEPAK 35 power accessories.

Expected: Cord is intact and firmly connected.

If a damaged cord is found, remove it from service and replace it with the correct approved cord. If resolved, stop.

5. Inspect the LIFEPAK 35 AC Power Adapter Assembly

Visually inspect the external adapter and attachment hardware for:

Do not use an adapter showing heat damage, arcing, exposed conductors, or abnormal odor.

Expected: Adapter assembly is physically intact with no obvious safety defect.

If damage is present, stop testing with that adapter and substitute a known-good approved LIFEPAK 35 adapter when available.

6. Reseat the External-Power Connections

With the device safely removed from patient use:

Expected: External-power connections seat securely without excessive looseness.

If reseating restores stable external power, verify operation before return to service and stop.

7. Check the Auxiliary Power Indicator

Connect the LIFEPAK 35 to the approved power adapter and verified AC source.

Observe the device’s external-power indication.

Stryker’s 2026 Performance Inspection Procedure states that the Auxiliary Power indicator should illuminate green when the defibrillator is connected to the auxiliary-power adapter and AC source, whether the defibrillator is on or off. The same procedure states that installed batteries automatically begin charging when connected to the power adapter.

Expected: Auxiliary Power indicator illuminates green and installed-battery charging behavior is present.

If the indicator remains off, continue troubleshooting.

8. Compare With a Known-Good AC Power Cord

When an approved compatible spare is available, substitute a known-good AC cord.

Do not use an improvised or unapproved cord merely because it physically fits.

Expected: External-power indication remains stable.

If the known-good cord resolves the problem, replace the defective cord and stop.

If the problem remains, continue.

9. Compare With a Known-Good LIFEPAK 35 Power Adapter

When available, connect a verified compatible LIFEPAK 35 AC power adapter.

Stryker identifies the LIFEPAK 35 AC Power Adapter Kit as a device-specific accessory that provides operating power and charges installed batteries.

Expected: Auxiliary Power indicator illuminates and external-power operation is restored.

If the known-good adapter resolves the problem, remove the failed adapter from service and replace it.

If the known-good adapter does not resolve the problem, suspect the device-side connection or internal power-management circuitry.

Stop external troubleshooting at that point.

10. Verify Battery and External-Power Switching Behavior

Install known-good, adequately charged LIFEPAK FLEX batteries and connect verified auxiliary power.

Confirm:

Stryker’s current PIP specifically includes an Auxiliary Power Switching Test and verifies transition from external power to battery operation.

Expected: Device remains operational and correctly changes power source without reboot, unexplained shutdown, or unstable indication.

If switching is unreliable, remove the device from service.

11. Check Installed-Battery Charging Response

With known-good batteries installed and verified external power connected, observe whether battery-charging indication appears and whether charge state progresses appropriately over time.

Stryker states that the LIFEPAK 35 power adapter charges batteries installed in the monitor/defibrillator, and the manufacturer’s PIP includes verification of battery-charging indication during power-management testing.

Expected: Installed batteries are recognized and charging behavior is present.

If the Auxiliary Power indicator is normal but batteries do not charge, investigate the complaint separately as a battery/charging fault rather than assuming loss of incoming AC power.

12. Perform Approved Operational Verification

After any correction, complete the facility-required operational checkout and applicable manufacturer-approved inspection procedure.

At minimum, confirm:

Stryker’s LIFEPAK 35 PIP includes power-on/self-test, indicator checks, auxiliary-power switching, power-source management, SHIFT Check, and Auto Test verification.

Expected: Device passes required testing with stable power behavior.

If the problem is resolved and all required checks pass, return the device to service according to department policy and stop.

If the Problem Persists

If the verified outlet, AC cord, adapter connections, approved power adapter, batteries, and external switching behavior have been evaluated without resolution, common external causes have been ruled out.

The fault is likely associated with the device-side external-power connection or internal power-management circuitry.

The LIFEPAK 35 should be:

Do not continue repeated power cycling, connector manipulation, or internal disassembly simply to force temporary operation.

Knowing when external troubleshooting is complete and escalation is required is proper Clinical Engineering troubleshooting.

Clinical Use Tip

Never troubleshoot unstable external power while the LIFEPAK 35 is the only defibrillator available for an active patient.

Move the patient to another verified device first when power reliability is uncertain. A unit that currently operates from batteries may still have reduced readiness if the external-power path cannot maintain charge.

Work Order Documentation (CCR Method)

CCR = Complaint, Cause, Resolution

Complaint

What was reported by the clinical staff.

Example:
"Clinical staff reported the LIFEPAK 35 operated from batteries but did not recognize AC/external power or show the Auxiliary Power indicator."

Cause

What was observed during troubleshooting.

Example:
"Verified wall power was present; troubleshooting isolated the failure to a defective LIFEPAK 35 AC power adapter that did not provide stable external power."

Resolution

What action was taken.

Example:
"Removed the failed adapter from service, installed a verified compatible replacement, confirmed green Auxiliary Power indication, battery charging, normal power-source switching, and successful operational testing."

Helpful Details to Include (If Known)

Final Thought

Power complaints should be worked from the wall inward: verify the source, cord, connections, adapter, indicators, batteries, and switching behavior before suspecting internal failure. Protect the patient first, stop when the fault exceeds safe external troubleshooting, and document the exact failure path clearly.

That is successful troubleshooting.

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