Changing Aquilion CT Tubes: Potential Issues at Installation

Replacing an X-ray tube can be a challenge and the risks are high for service providers. Our team is here to help you avoid potential issues when installing a Toshiba/Canon* Aquilion CT tube. Here are instructions for how to address potential issues at installation.

Potential Issues at Installation

  • Over mA Error, Over mA along with Arc Error, and Under mA (Set) Error
    • Do not assume the replacement tube is DOA. The filament characteristics of the new tube and the old tube are different.
      • Load standard IF data for the generator type, warm the tube up to 50% OLP and perform IF adjustments.
      • Save the IF data to a file, then perform IF adjustments again. Compare the two files. There should be zero differences greater than or equal to four. If there are differences greater than or equal to four, the filaments are unstable. Continue to perform IF adjustments and comparisons until there are zero differences greater than or equal to four.
      • For Under mA error: If the wrong dielectric was used, this error will occur at specific kV, mA and focus size combinations and tube OLP. The solution is to clean the high voltage cable and the tube insert, then apply the correct dielectric for cable type.
        • DSI cable: use high voltage grease
        • Claymount cable: use high voltage silicone oil
  • HV overcurrent error or HV overcurrent along with Arc error
    • This is not a tube arc—it is a generator arc. Make sure the HV cable is installed properly on the generator.
  • Image quality issues
    • Smudge or center dot artifact: Check the tube alignments
    • Soft ring artifact: Check front to back tube alignment
    • Blurry or out of focus images: Check left to right tube alignment
    • Zebra artifact on MPR reconstructions: Check left to right tube alignment


It’s best to revisit the site and perform IF adjustments two weeks after installing the new tube. The resistance of the filaments changes due to use.

If you run into any of these issues during installation and are unable to correct the error, give our team a call.

This is only one small way Richardson Healthcare can help service providers save money and increase uptime. Enroll in our Toshiba CT service training course today!

24/7 Tech Support and Parts Hotline – (704) 739-3597

Visit to learn more about our CT service training, QA3 replacement parts, and tube solutions including the ALTA750®. The ALTA750® is a form, fit, and function replacement for the Toshiba/Canon Medical Systems CXB-750D/4A CT tube.

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