• Topic ID: id_18480251
  • Version: 4.0
  • Date: Jan 20, 2020 8:32:31 PM

TGPHD Replacement

Prerequisites

Overview

This procedure defines the steps necessary to replace the TGPHD board.

1 Removing The TGPHD

Procedure

  1. Remove the gantry right side cover.
  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. Notice Image
    • notice
    • Always turn OFF the HVDC before the 120VAC. Turning OFF 120VAC power before HVDC power can result in equipment damage.
  3. Turn off all three (3) switches (Axial Drive, HVDC, and 120VAC) on the Service Switch Panel.
  4. Perform all required LOTO activities.
    note:

    Front and rear access is required for this procedure.

  5. Remove gantry left side cover. If further access is required, remove top and rear covers.

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

  6. Remove the 8 thumbscrews in the TGPHD cover, then remove the cover.
  7. Disconnect all cabling into the TGPHD.
    note:

    If the cables are not labeled, label them as they are removed.

  8. Remove the cabling assembly plate.

    Figure 1. TGPHD

  9. Remove the eight (8) screws attaching the TGPHD board.
  10. Remove the defective TGPHD.

2 Install TGPHD

Procedure

  1. Put the new TGPHD board in place.
  2. Secure the board by replacing the eight (8) screws.
  3. Install the cable assembly plate.
  4. Carefully install all of the removed cables, making sure that no pins are bent during engagement.
  5. Remove LOTO, and power up everything except the gantry.
  6. Before powering ON the 120 VAC gantry power, open a shell (terminal) window on the console and type the following

    cd /usr/g/fw ENTER

    touch tgpFtp ENTER

    note:

    These commands must be performed to assure that the FLASH download procedure successfully downloads the TGPHD firmware from the OC, regardless of the status of the TGPHD programming.

  7. Turn ON all three (3) switches (Axial Drive, HVDC, and 120VAC) on the Service Switch Panel and press the E-stop reset.
  8. Execute Flash download query and update. Refer to the Flash download procedure if necessary.
  9. Perform the power supply adjustment procedure in the Finalization section of the TGPHD Power Supply Replacement.
  10. Turn off the Axial Drive, HVDC and 120 VAC service switches.
  11. Replace the TGP cover.
  12. Replace gantry covers except for the right side cover that allows access to Service Switch Panel.
  13. Turn on the 120 VAC, HVDC and Axial Drive service switches.
  14. Replace gantry right side access cover.

3 Finalization

Procedure

  1. Perform the System Scanning Test from the Functional Checks folder.