• Topic ID: task_xyd_jfn_2jb
  • Version: 4.0
  • Date: Dec 29, 2020 1:04:50 AM

Collimator Plastic Window Replacement

Prerequisites

Overview

Over time, the Lexan covering the collimator input windows can get brittle and break apart leading to image quality problems. When this occurs, it is recommended that the input window be replaced utilizing part number 2390458.

note: This procedure is only to be performed in conjunction with a Tube change.

1 Procedure

Procedure

  1. Position the table to its lowest position if not already done.
  2. Stop the rotor of X-ray tube in case of Liquid Bearing Tube before HVDC off. Refer to Liquid Bearing Tube Rotor stop procedure for details.
  3. Remove the gantry right side cover.
  4. Turn off the three (3) main power switches (Axial Drive, HVDC and 120VAC) on the Service Switch Panel. Power down the console and perform LOTO procedures to lock out power on the gantry.
    note: Always turn OFF HVDC before 120VAC. Turning OFF 120VAC power before HVDC power can result in equipment damage.
  5. To aid in access to the Collimator, remove the gantry left side cover, top covers, front cover and rear cover.
  6. Rotate the Gantry until the Tube reaches the 6 o'clock position.
  7. Remove the CCB chassis cover from the Collimator Assy by loosening four fasteners.

    Figure 1. CCB Chassis Cover Removal

  8. Using a straight slot screwdriver, drive the collimator filters to the home position. See Figure 2. This reduces the chance of contamination and potential image quality problems.

    Figure 2. Collimator Filter

  9. Unscrew fourteen (14) M2.5 screws and washers to remove two Secondary End Apertures and Shield Plates as shown in Figure 3.

    Figure 3. Collimator Plastic Window Removal

  10. Use the new Collimator Plastic Window to replace the defective window, clean the underside of any debris.
  11. Clean any debris away from the mounting surface of the Secondary End Aperture by using Alcohol before installing.
  12. Fix all components by screwing fourteen M2.5 screws and washers, apply torque of 0.7±0.07Nm.
  13. Reinstall the CCB chassis cover to the Collimator Assy.
  14. Remove LOTO and install all of the gantry covers except right side cover.
  15. Enable 120VAC, HVDC and Axial Drive service switches panel. Press the table drives enable button on the lower right corner of the service switch panel.
  16. Install the right side cover.

2 Finalization

No finalization steps.