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What This Guide Helps With
This guide helps troubleshoot Err 144 on a CONMED System 2450 / 5000 Series Electrosurgical Unit when the RF Controller and Monitor power readings do not match. This may indicate inaccurate RF output monitoring, feedback disagreement, sensing circuit problems, or a possible internal output control issue.
Because an ESU must accurately control and monitor delivered RF energy, this error should be treated as a patient safety concern until the unit is removed from use, tested under controlled conditions, and repaired or cleared for service.
Step-by-Step Troubleshooting
Ensure Patient Safety First
- Remove the ESU from patient use if Err 144 appears during startup, setup, activation, or clinical use.
- Disconnect the unit from active clinical use.
- Notify clinical staff that the ESU has reported an RF output power monitoring mismatch.
- Provide a replacement ESU if electrosurgery is still required.
- Do not continue using the generator until the fault is resolved and output performance is verified.
Expected outcome: Patient care continues without relying on an ESU with unresolved RF power monitoring disagreement.
Why it matters: Err 144 indicates that the RF Controller and Monitor are not agreeing on output power. An ESU with questionable output monitoring should not be trusted for patient use.
Verify the Reported Error and Behavior
- Power the ESU on and confirm whether Err 144 is displayed.
- Determine whether the error occurs at startup, during POST, only during activation, only in a specific mode, or intermittently.
- Confirm whether the unit allows activation or locks out use.
- Record the selected mode, power setting, accessory used, and output jack involved when the error occurs.
Expected outcome: Err 144 is either reproducible or clearly tied to a specific activation condition.
Why it matters: This confirms a true system-reported power monitoring mismatch instead of a setup issue, user report mismatch, or one-time transient fault.
Check Power Source and Basic External Conditions
- Verify the ESU is connected to a known-good hospital-grade outlet.
- Confirm the power cord is fully seated and undamaged.
- Check for obvious signs of damage, overheating, liquid intrusion, or contamination.
- Power cycle the unit and observe whether Err 144 returns.
Expected outcome: The ESU powers normally without external power instability or visible damage.
Why it matters: Before investigating internal RF monitoring circuits, rule out simple power or physical-condition problems.
Check ESU Accessories and Output Connections
- Remove all accessories from the ESU.
- Inspect monopolar pencils, bipolar forceps, footswitches, return electrode cables, adapters, and output connectors for damage or contamination.
- Reconnect only the minimum required accessories for controlled testing.
- Use known-good accessories when attempting to reproduce the issue.
Expected outcome: The error is not caused by a damaged accessory, contaminated connector, or abnormal load path.
Why it matters: Faulty accessories or poor output connections can create abnormal RF feedback conditions that may appear as output monitoring disagreement.
Confirm the Error Is Not Mode- or Accessory-Specific
- Use appropriate ESU test equipment and a controlled load.
- Check whether Err 144 appears in one mode or multiple modes, such as Cut, Blend, Coag, Spray, or Bipolar.
- Test one output configuration at a time.
- Record whether the fault follows a specific mode, output connector, power range, or accessory configuration.
Expected outcome: The fault pattern is narrowed to a specific mode, output path, or general RF monitoring issue.
Why it matters: Err 144 may be related to the voltage or current feedback circuits for the activated mode. Identifying the affected mode helps isolate the problem.
Verify Displayed Power Versus Actual Output Power
- Connect the ESU to an approved ESU analyzer with the correct load for the mode being tested.
- Set the unit to a controlled power setting.
- Activate the ESU according to safe test procedure.
- Compare measured output power to the displayed power setting.
Expected outcome: Actual measured output power should reasonably match the displayed power setting within applicable service limits.
Why it matters: Err 144 means the RF Controller and Monitor power levels do not agree. Measuring actual output helps determine whether the problem is true output control or feedback and monitoring disagreement.
Evaluate Monitor Feedback
- Use available service diagnostics, such as DACview if applicable, to observe Monitor readings during controlled activation.
- Compare Monitor-reported voltage, current, and calculated power values against expected behavior.
- Look for readings that are missing, stuck, noisy, scaled incorrectly, or inconsistent with measured ESU analyzer output.
Expected outcome: Monitor feedback should track output changes logically as power settings and modes change.
Why it matters: If Monitor feedback does not match actual output, the issue may be in the Monitor sensing path or feedback circuitry.
Compare RF Controller and Monitor Sensing Channels
- During controlled bench testing, compare voltage and current sensing channels for both the RF Controller and Monitor.
- Check whether the mismatch follows a specific mode, output connector, power range, voltage feedback channel, current feedback channel, or general controller and monitor disagreement.
- Do not continue repeated activation if abnormal output behavior, arcing, overheating, or unstable readings are observed.
Expected outcome: The mismatch is isolated to either the RF Controller side, Monitor side, or mode-specific feedback path.
Why it matters: Err 144 is specifically a disagreement between RF Controller and Monitor power levels. The repair direction depends on which side is reporting incorrectly.
Inspect External Signs Before Considering Internal Failure
- Check output connectors for damage, looseness, contamination, or evidence of arcing.
- Inspect accessory sockets for wear, burning, cracked plastic, or fluid contamination.
- Watch for abnormal fan operation, burning smell, heat, or unusual sounds during controlled testing.
- Stop testing immediately if unsafe output behavior is observed.
Expected outcome: No external connector damage or unsafe operating condition is present.
Why it matters: Physical output damage can affect RF delivery and sensing. Safety concerns should stop testing immediately.
Stop If the Issue Is Resolved
- If the error clears after replacing a faulty accessory, correcting a connection issue, or resolving an external setup problem, perform full functional testing.
- Verify output power using an ESU analyzer.
- Confirm the error does not return through startup and controlled activation.
- Complete electrical safety testing if required by facility policy.
- Return the ESU to service only after it passes all required checks.
Expected outcome: Err 144 no longer appears, and measured output performance is acceptable.
If the Problem Persists
If Err 144 continues after external power checks, accessory checks, output connector inspection, controlled load testing, and output verification, the likely issue is internal to the ESU.
Persistent Err 144 may indicate RF Controller power sensing disagreement, Monitor voltage or current feedback problems, a mode-specific RF feedback circuit fault, output sensing circuit failure, Controller assembly fault, or an RF voltage/current feedback circuit issue for the activated mode.
- External power, accessories, output connections, and basic setup have been ruled out.
- Remove the device from service.
- Label it Out of Service.
- Send it for repair or bench evaluation.
- Do not continue clinical use until the RF output and monitoring systems are verified.
Knowing when to stop is proper troubleshooting. An ESU reporting disagreement between its RF Controller and Monitor should not be trusted for patient use until repaired and fully tested.
Clinical Use Tip
Never troubleshoot Err 144 on an active patient. Move the patient or procedure to a known-good backup ESU first. An unresolved RF power mismatch can affect output confidence and patient safety.
Work Order Documentation (CCR Method)
CCR = Complaint, Cause, Resolution
Complaint
What was reported by the clinical staff.
Example:
"CONMED System 2450 / 5000 Series ESU reported Err 144. RF Controller and Monitor power levels did not match during activation testing. Unit removed from service for evaluation."
Cause
What was observed during troubleshooting.
Example:
"Err 144 reproduced during controlled bench testing. External power, accessories, output connections, and basic setup were checked. Fault appears related to internal RF power monitoring, voltage/current feedback, or Controller/Monitor sensing disagreement."
Resolution
What action was taken.
Example:
"Removed ESU from service and labeled Out of Service. Verified fault with ESU analyzer testing. Recommended bench repair and further evaluation of Controller assembly and RF voltage/current feedback circuits for the affected activation mode."
Helpful Details to Include (If Known)
- Alarm behavior
- Accessories swapped
- Power behavior
- Environmental factors
- Indicator lights
- Final device status
Final Thought
Err 144 should be treated as a serious ESU output monitoring fault. Start with patient safety, verify the exact error, rule out power, accessories, connections, and setup, then use controlled testing to compare displayed power, measured output, and RF Controller/Monitor feedback. If the mismatch persists, escalation is appropriate because the generator may not be accurately confirming its own RF output behavior. Clear CCR documentation protects patients, staff, and the repair process.
That is successful troubleshooting.