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What This Guide Helps With
Helps isolate abnormal differential scattergrams or channel-priming failures caused by samples, reagents, tubing, consumables, settings, or external fluid-path conditions.
Step-by-Step Troubleshooting
1. Protect Patient Testing and Confirm the Reported Condition
Do not continue reporting potentially unreliable differential results while the analyzer is producing abnormal scattergrams or cannot properly prime a measurement channel. Redirect testing to another verified analyzer or approved backup process when needed.
Confirm whether the problem affects all samples, one sample type, one measurement channel, or only specific racks or specimens. Record any displayed message and determine whether the problem began after reagent replacement, maintenance, cleaning, restart, or extended idle time.
Expected outcome: The affected function and scope of the problem are clearly identified. If the condition was sample-specific and repeat testing on a verified specimen is normal, troubleshooting can stop after appropriate result verification and documentation.
2. Check Reagent and Waste Conditions
Verify that all required reagents are present, correctly installed, properly connected, within their approved use period, and not visibly contaminated, empty, kinked, or improperly positioned.
Inspect reagent pickup lines and external connections for loose fittings, collapsed tubing, bubbles, leaks, or evidence that a container was installed incorrectly. Confirm the waste path is not full, obstructed, or incorrectly connected.
Expected outcome: Reagents and waste connections are correctly installed with no obvious restriction, leak, or air entry. If correcting an external reagent or waste condition restores normal priming and scattergrams, troubleshooting can stop after successful verification.
3. Inspect the Sample and Preanalytic Conditions
Use a properly collected, adequately mixed specimen suitable for analyzer testing. Inspect for visible clotting, insufficient volume, unusual settling, improper tube type, or other obvious preanalytic problems.
If appropriate, compare with a known-good specimen rather than repeatedly testing a questionable sample.
Expected outcome: A suitable, well-mixed specimen produces consistent results. If the abnormal scattergram follows only one specimen while known-good specimens test normally, address the sample issue rather than the analyzer.
4. Verify External Fluid-Path Conditions
Inspect accessible reagent and aspiration tubing for kinks, pinches, loose connections, trapped air, crystallized residue, or routing that could restrict flow.
Check that recently serviced or replaced external tubing and reagent connections were returned to their normal positions.
Do not open internal valves, manifolds, pumps, or measurement assemblies as part of routine external troubleshooting.
Expected outcome: Accessible fluid paths are secure and unobstructed. If correcting an external restriction or air leak allows the channel to prime normally, troubleshooting can stop after verification.
5. Run Approved Prime, Rinse, or Cleaning Functions
Use only normal operator-accessible or Clinical Engineering-approved maintenance functions documented for the analyzer. Perform the appropriate prime, rinse, or cleaning process for the affected channel.
Observe whether fluid movement appears normal and whether repeated air introduction, incomplete priming, or persistent warnings occur.
Expected outcome: The channel completes its normal fluid preparation sequence without repeated failure. If normal priming returns and subsequent controls or known-good samples produce acceptable scattergrams, troubleshooting can stop.
6. Check for Reagent Change or Lot-Related Timing
Determine whether the condition began immediately after changing a reagent container, lot, or consumable. Verify that the correct reagent was installed in the correct position and that required identification or setup information was entered correctly.
Do not alter calibration or analytical configuration merely to make an abnormal scattergram appear normal.
Expected outcome: Correct reagents and associated configuration are confirmed. If correcting a reagent installation or identification issue restores normal operation, troubleshooting can stop after verification.
7. Compare Channels and Known-Good Operation
Determine whether the problem is isolated to one analytical channel while other channels function normally. Run applicable controls or a known-good specimen according to laboratory procedure.
A persistent failure limited to one channel after external causes are eliminated may indicate a service-level fluidic, optical, sensing, or reaction-path problem.
Expected outcome: Either normal channel performance is confirmed, or the failure is clearly isolated for escalation.
8. Perform Final Functional Verification
After correction, perform the required analyzer checks using approved controls, known-good specimens, or laboratory verification procedures.
Confirm that priming completes, scattergrams appear consistent with expected analyzer behavior, no related warnings remain, and patient testing can be resumed according to laboratory policy.
Expected outcome: The analyzer completes testing normally and produces verified results. If verification passes, return the analyzer to service and stop troubleshooting.
9. Remove From Service if Reliability Is Not Restored
If the affected channel will not prime, scattergrams remain abnormal across appropriate specimens, controls fail, or fluid handling remains unreliable, do not return the analyzer to patient testing.
Expected outcome: Unreliable analytical performance is prevented from affecting patient results.
If the Problem Persists
Common external causes such as specimen quality, reagent installation, accessible tubing, waste conditions, priming, and obvious configuration issues have been ruled out.
The remaining problem may involve internal fluidics, valves, pumps, reaction chambers, optical detection, sensors, reagent delivery, or service-level configuration.
The analyzer should be:
- Removed from service
- Labeled Out of Service
- Sent for repair or bench evaluation
- Evaluated using appropriate manufacturer documentation and approved test equipment
- Repaired or configured only by qualified personnel
After repair, complete all required analyzer checks, quality-control verification, and applicable laboratory return-to-service testing before patient results are released.
Knowing when to stop external troubleshooting and escalate a persistent analytical failure is proper troubleshooting.
Clinical Use Tip
Do not release differential results from a channel producing unexplained abnormal scattergrams until analyzer performance has been independently verified.
Work Order Documentation (CCR Method)
CCR = Complaint, Cause, Resolution
Complaint
What was reported by the clinical staff.
Example:
"Laboratory staff reported repeated abnormal WBC differential scattergrams and failure of the affected channel to prime normally."
Cause
What was observed during troubleshooting.
Example:
"Clinical Engineering found an improperly seated reagent connection allowing air into the accessible reagent line."
Resolution
What action was taken.
Example:
"Reseated the reagent connection, completed the approved prime sequence, verified normal channel operation with laboratory controls, and returned the analyzer to service."
Helpful Details to Include (If Known)
- Exact displayed message
- Affected analytical channel
- Whether all or only selected specimens were affected
- Reagent status and recent replacements
- Visible bubbles or tubing restrictions
- Waste condition
- Prime or rinse results
- Known-good specimen results
- Control results before and after correction
- Whether the problem followed a reagent change or maintenance
- Final analyzer status
Final Thought
Protect patient results first, then work from specimens and external reagent conditions toward the analyzer. Verify normal operation before assuming an internal failure, escalate persistent channel problems appropriately, and document what was found and corrected.
That is successful troubleshooting.