Asset Type

Defibrillator

Manufacturer

ZOLL

Model

X Series

What This Guide Helps With

This guide assists Clinical Engineering in troubleshooting situations where a ZOLL X Series defibrillator reports pads or electrode detection errors. These may appear as messages such as “Pads Not Detected,” “Check Pads,” “Replace Electrodes,” or failure to recognize therapy electrodes. Many causes are related to pad connection, cable condition, or accessory issues rather than internal device failure.

Step-by-Step Troubleshooting

Verify the Device Is Not in Active Clinical Use

• Ensure the defibrillator is not connected to a patient before troubleshooting. Move the patient to another device if necessary.

Check the Pad Connector at the Defibrillator

• Confirm the therapy electrode cable is fully seated in the therapy port on the X Series.
• Remove and reconnect the cable.
• Ensure the connector is properly aligned and locked.
• Loose or partially seated connectors are a common cause of pad detection errors.

Inspect the Pads (Electrodes)

• Check the therapy pads for:
• Expiration date
• Damaged adhesive or gel
• Broken lead wires
• Packaging damage
• Expired or damaged pads may not be detected correctly by the device.

Verify the Correct Pad Type

• Ensure the pads being used are compatible with the ZOLL X Series (such as ZOLL OneStep electrodes or approved equivalents).
• Using incompatible pads may cause detection or impedance errors.

Check the Therapy Cable

• Inspect the therapy electrode cable for:
• Bent pins
• Cracked insulation
• Kinks or stress near the connector
• Loose strain relief
• Damage to the cable can interrupt electrode detection.

Swap with Known Good Pads

• Connect a new set of pads from sealed packaging.
• If the error clears, the original pads were likely defective or expired.

Test with a Known Good Therapy Cable (If Available)

• If another compatible cable is available:
• Disconnect the existing therapy cable
• Connect the known good cable
• Attach pads and power on the device
• If the error resolves, the original cable is likely faulty.

Check for Debris in the Connector Port

• Look inside the therapy cable port on the defibrillator.
• Ensure there is no debris, bent contacts, or contamination preventing proper electrical contact.

Power Cycle the Device

• Turn the device off, wait several seconds, and power it back on.
• Temporary detection errors can sometimes clear with a restart.

Perform a Functional Test

• After reconnecting pads:
• Verify the device recognizes the pads
• Check that impedance values appear normal
• Confirm no electrode warnings remain

If the Problem Persists

If pads and therapy cables have been verified or replaced and the device still reports electrode detection errors, the issue may be internal. Possible internal causes include:

• Therapy connector board failure
• Internal cable harness issues
• Defibrillator therapy module faults

At this point:

• Remove the device from service
• Label it Out of Service
• Send the unit for bench evaluation or authorized repair

Recognizing when common external causes have been ruled out is an important part of proper troubleshooting.

Clinical Use Tip

Never troubleshoot therapy electrodes while the defibrillator is attached to a patient. Always transfer the patient to another monitor/defibrillator before testing pads or cables to prevent interruption of life-saving therapy.

Work Order Documentation (CCR Method)

CCR = Complaint, Cause, Resolution

Complaint

What was reported by the clinical staff.

Example:
Staff reported the ZOLL X Series defibrillator displaying “Pads Not Detected” despite new electrodes being connected.

Cause

What was observed during troubleshooting.

Example:
Inspection found the therapy electrode cable had visible strain damage near the connector, causing intermittent electrode detection.

Resolution

What action was taken.

Example:
Therapy cable replaced and device tested with new pads. Pads detected normally and device passed functional check.

Helpful Details to Include

• Pads expiration date verified
• Pad connector reseated
• Therapy cable inspected and/or replaced
• Known-good pads tested
• Connector port checked for debris
• Alarm or message observed
• Final device operational status

Final Thought

Pad detection issues are frequently caused by simple accessory problems such as expired electrodes, loose connectors, or damaged therapy cables. By starting with these external checks, Clinical Engineering can resolve many problems quickly while maintaining patient safety. Proper documentation and escalation when internal faults are suspected ensures the defibrillator remains reliable for emergency use.

That is successful troubleshooting.