• Topic ID: id_11039093
  • Version: 4.0
  • Date: Nov 27, 2020 2:16:20 AM

Filter Assembly Replacement

Prerequisites

This procedure describes the replacement procedure for the collimator filter assembly.

Procedure

  1. Remove gantry covers as required.

    Refer to Parts Replacement > Gantry > Enclosure > (Cover Removal Procedure).

  2. Turn OFF all 3 gantry service switches (Axial Drive, HVDC, 120 VAC).
  3. Position a drop cloth below the Collimator to collect any hardware that might be dropped.
  4. Follow the procedure for removing the Collimator Control Board.

    Refer to Collimator Control Board (CCB) Replacement

    note:

    See Figure 1 for the location of parts related to the Filter Assembly replacement.

    Figure 1. Filter Assembly Replacement

  5. Follow the procedure for removing the Cam Motor Driver Modules Cam Motor Driver Module Replacement.
  6. Remove driver covers on motor mount assembly and set aside.
  7. Remove the CAM A & B encoder cable ring terminals & washers.
  8. Return the screws & washers to their original location after removing the ring terminals.
  9. Slide the grommet on the CAM A & B encoder cables out of the frame mount to fully disconnect the encoder cables from the frame.
  10. Remove the Filter PWB Mount Bracket by removing the six pan head M4 mounting screws and set aside.
  11. Remove the four hex socket M4 frame mounting screws.
    note:

    Do not damage the fragile aluminum, graphite & copper filter assembly that extends into the Collimator frame during the Filter removal or new Filter installation.

  12. Lift the Filter Assembly from the steel Collimator frame and set to the side.
  13. Remove the new Filter Assembly from the shipping box.
  14. Seat the new Filter Assembly on the Collimator alignment pins.
  15. Place the old Filter Assembly in to the shipping box.
  16. On the new Filter Assembly, insert the four hex socket M4 frame mounting screws and torque to:
  17. Replace the Filter PWB Mount Bracket by installing all six pan head screws loosely, then tighten and torque to 3 ± 0.3 N-m.
  18. Follow the procedure for reconnecting the Cam Motor Driver Modules.
  19. Replace the driver covers on motor mount assembly.
  20. Follow the procedure for reconnecting the Collimator Control Board.
  21. Remove the screw & washer for the ring terminals & use to secure the CAM A & B ring terminals & tighten.
  22. Replace the top cover of the Collimator using the five pan head mounting screws with spring washers and tighten.
    note:

    Ensure the Cam Driver Leads are outside of the cover.

  23. Remove the drop cloth and follow the procedures for closing the gantry.

Finalization

  1. Perform Collimator Aperture Tests.
  2. Perform Collimator Functional Diagnostic Tests.
    note: Perform below procedures if there are artifact seen in the images.
  3. Perform Plane of Rotation (POR) Alignment.
  4. Perform Beam on Window (BOW) Alignment Process.
  5. Perform CBF/SAG Alignment Process.
  6. Perform ISO Alignment Process.
  7. Perform HOT ISO Alignment.
  8. Perform Collimator Calibration.
  9. Perform Detailed Calibration.
  10. Perform Fast Calibration.
  11. Perform System Scanning Test.
  12. Perform Quality Assurance Test.
  13. Perform Save System State.