On this page
Asset Type
Manufacturer
Model
What This Guide Helps With
Table movement, indexing, positioning, or height errors caused by obstructions, controls, accessories, power, or positioning system faults.
Step-by-Step Troubleshooting
1. Ensure Patient Safety First
Do not continue scanning if the table is moving unpredictably, not stopping correctly, or positioning inaccurately.
Action:
- Stop the scan or planned scan.
- Keep the patient still and supported.
- Remove the patient from the scanner table if movement is unsafe or unreliable.
- Use another CT room if the exam is urgent.
Expected outcome:
Patient safety is maintained before troubleshooting begins.
If this resolves the immediate safety concern, stop and document the issue.
2. Verify the Reported Table Problem
Confirm the exact behavior before assuming a table failure.
Action:
- Ask staff what occurred.
- Determine if the issue is: table will not move, table moves intermittently, table height will not adjust, table indexing is inaccurate, table position does not match console display, table stops during movement, or table produces abnormal noise.
- Note whether the issue occurs from the gantry controls, table controls, or operator console.
Expected outcome:
The table motion or positioning problem is clearly identified and reproducible.
3. Confirm the Table Is Clear of the Patient and Staff
Physical obstruction is one of the first things to rule out.
Action:
- Ensure the patient, staff, blankets, straps, IV lines, tubing, or accessories are not restricting table travel.
- Check that nothing is caught between the tabletop, base, gantry opening, or floor area.
- Verify the table is not contacting another object in the room.
Expected outcome:
Table travel path is clear.
If the table moves normally after clearing the obstruction, return the unit to service after verifying safe operation and documenting the finding.
4. Check Emergency Stop and Motion Inhibit Conditions
A CT table may be prevented from moving if an emergency stop or safety interlock is active.
Action:
- Check gantry and console emergency stop buttons.
- Confirm none are pressed or latched.
- Reset only according to site procedure.
- Look for system messages indicating motion inhibit, collision prevention, or safety stop.
Expected outcome:
No emergency stop or safety inhibit is active.
If resetting a known activated emergency stop restores table motion, verify full table operation before returning to service.
5. Inspect Table Controls and Gantry Control Panels
A stuck or damaged control can cause no movement, intermittent movement, or unexpected behavior.
Action:
- Inspect table-side controls for stuck buttons, damage, fluid intrusion, or loose panels.
- Test table motion from available control locations if safe.
- Compare behavior between the operator console and gantry/table controls.
Expected outcome:
Controls respond consistently and do not appear stuck, damaged, or contaminated.
If one control location fails but another works normally, document the failed control location and remove the scanner from service if safe operation cannot be guaranteed.
6. Check Table Position Limits
The table may stop moving if it has reached a mechanical or programmed travel limit.
Action:
- Verify whether the table is already at its upper, lower, in, out, or longitudinal travel limit.
- Attempt movement in the opposite direction if safe.
- Observe whether the system displays a limit, positioning, or travel warning.
Expected outcome:
The table either moves away from the limit or confirms a travel-limit condition.
If the table was simply at a travel limit and normal movement resumes, verify full operation and document the finding.
7. Verify Patient Weight and Table Load
Excessive load or uneven loading can affect table lift and positioning accuracy.
Action:
- Confirm patient weight is within the scanner table’s rated capacity.
- Check for excessive accessory weight on the table.
- Ensure the patient is centered and not causing uneven table loading.
- Remove unnecessary accessories before retesting.
Expected outcome:
The table is not overloaded or unevenly loaded.
If table motion returns after correcting load conditions, document the cause and remind staff to follow table weight and positioning limits.
8. Inspect Tabletop, Cradle, and Accessories
Misaligned or loose accessories can interfere with table motion or indexing.
Action:
- Inspect the tabletop/cradle for visible damage, loose hardware, cracked covers, or abnormal gaps.
- Verify head holders, pads, straps, positioning aids, and extension accessories are correctly installed.
- Remove nonessential accessories and retest table movement if safe.
Expected outcome:
No accessory or tabletop issue is interfering with table travel.
If an accessory was causing the issue, remove it from use and document the correction.
9. Check for Abnormal Noise, Binding, or Vibration
Mechanical resistance can indicate a table drive, rail, bearing, lift, or alignment issue.
Action:
- Move the table slowly through a limited safe range with no patient present.
- Listen for grinding, clicking, scraping, slipping, or sudden stops.
- Watch for jerky movement or uneven lift.
- Stop testing immediately if motion appears unsafe.
Expected outcome:
Table motion is smooth and controlled.
If abnormal noise, binding, or vibration is present, remove the scanner from service and escalate for repair.
10. Verify Console Position Display and Table Position Accuracy
A positioning mismatch can affect scan planning and image location accuracy.
Action:
- Compare displayed table position with observed physical table position.
- Check whether table coordinates update smoothly during motion.
- Attempt a controlled positioning movement only with no patient present.
- Confirm whether the system reports positioning, encoder, or table feedback errors.
Expected outcome:
Displayed table position matches physical table movement.
If the table moves but position feedback is inaccurate, remove the scanner from service. Incorrect table position can directly affect exam accuracy.
11. Perform a Controlled System Restart if Safe
Temporary software or communication faults can affect table control.
Action:
- Confirm no patient is on the table.
- Follow department downtime and restart procedure.
- Power down or restart the CT system according to site policy.
- Allow the system to fully initialize.
- Retest limited table movement without a patient.
Expected outcome:
Table motion and position display return to normal if the issue was temporary.
If the issue clears after restart, perform a safe operational check and document the restart and successful table test.
12. Check for Room Power or System Power Issues
Table drive and control systems require stable power.
Action:
- Verify the CT system is fully powered and not in a partial shutdown state.
- Check for facility power events, breaker trips, UPS alarms, or recent room power interruptions.
- Confirm the operator console and gantry are communicating normally.
- Do not access internal power components unless trained and authorized.
Expected outcome:
No external facility power issue is contributing to the table fault.
If power instability is suspected, involve facilities and vendor service as appropriate.
13. Review Error Messages and Event History
Table errors may be linked to position sensors, drive faults, collision detection, or communication issues.
Action:
- Record the exact error message or code shown on the console.
- Note when the error occurs: startup, table movement, scan setup, or during exam.
- Capture screenshots or photos if allowed by facility policy.
- Include gantry/table position and patient load status at time of failure.
Expected outcome:
The failure pattern is documented clearly for repair escalation.
If the Problem Persists
If table motion or positioning errors continue after checking patient safety, obstructions, emergency stops, controls, accessories, load conditions, table limits, power status, and restart behavior, the likely cause is internal to the table drive, lift system, position feedback system, encoder, interlock circuit, motion controller, or CT system communication pathway.
The device should be:
- Removed from service
- Labeled Out of Service
- Escalated for Philips service, vendor repair, or qualified bench/system evaluation
Do not continue patient scanning if table position is unreliable. Knowing when to stop is proper troubleshooting.
Clinical Use Tip
Never troubleshoot CT table motion problems with a patient on the table unless the action is required to safely remove the patient. Unexpected movement, failure to stop, or incorrect positioning can create patient injury risk and scan accuracy problems. Move the patient to a backup device or alternate imaging pathway first so therapy and diagnostic care can continue safely.
Work Order Documentation (CCR Method)
CCR = Complaint, Cause, Resolution
Complaint
What was reported by the clinical staff.
Example:
"CT staff reported the Philips Brilliance CT table would not advance into the gantry and displayed a table positioning error during exam setup."
Cause
What was observed during troubleshooting.
Example:
"Clinical Engineering found no patient obstruction, no activated emergency stop, and normal accessory setup, but table motion remained intermittent with inaccurate position feedback."
Resolution
What action was taken.
Example:
"Scanner was removed from service, labeled Out of Service, error details were documented, and Philips service was contacted for table drive and position feedback evaluation."
Helpful Details to Include (If Known)
- Exact table error message or code
- Whether issue occurred with or without patient loaded
- Patient weight if relevant
- Direction of failed motion: up, down, in, out, longitudinal
- Whether gantry controls and console controls behave differently
- Emergency stop status
- Obstruction check completed
- Accessories removed or swapped
- Abnormal noise, vibration, or binding
- Console position display behavior
- Restart attempted
- Final scanner status
Final Thought
CT table motion problems should be handled carefully because they affect both patient safety and exam accuracy. Start with external causes such as obstructions, controls, emergency stops, accessories, and load conditions before escalating. If motion is abnormal, noisy, unpredictable, or position feedback is inaccurate, remove the scanner from service and document the failure clearly.
That is successful troubleshooting.