• Topic ID: id_16157855
  • Version: 4.0
  • Date: Jan 20, 2020 8:32:57 PM

24V Power Supply Replacement

Prerequisites

Overview

This procedure is for the Global PET/CT Table, with fixed position IMS and the GT1700V Table.

Procedure

  1. Raise the Table to maximum height.
    note:

    If the Table can not be raised due to a malfunction of a 24V Power Supply, connect J1 and J111 connectors to provide 120VAC directly to the Inverter Assy, then raise the Table using INV_UP switch on the GTCB board. After completion of Table raising, disconnect J1 and J111 connectors, and re-connect theses connectors to the original cable connections.

    Figure 1. J1 and J111 Cable Connectors

  2. Move the Cradle to OUT limit position.
  3. Remove power from Table by turning off 120VAC, Axial Drive and HVDC switches on Service Switch Panel.
  4. Remove the following Table Cover:

    • IMS Rear Cover

    • IMS Side Cover (Right)

    • Front Base Cover

    • Base Cover (Right)

    • Front/Rear Side Plate (Right)

    • Front Leg Plate (Right)

    Figure 2. Table Covers

  5. Cut any tie-wraps holding the Power Supply cables to the Table frame.
  6. Disconnect the following cable connectors:

    • -> J100, 5114075 cable connector

    • -> J101, 5114074 cable connector

    • -> Cradle Motor Driver

    • -> J31, GTCB Assy

  7. Unscrew 4 screws, and take the Power Supply with the bracket out the Table.

    Figure 3. 24V Power Supply Removal

  8. Connect all cable connectors, and put the new Power Supply on the floor.
  9. Power up the Table from the Service Switch Panel.
  10. Measure the voltage on the Test Point on the GTCB, and check that it is within +22.8VDC ~ +25.2VDC. If it falls outside these limits, adjust it by turning the potentiometer.

    Figure 4. 24V Power Supply

  11. Turn off all 3 switches (Axial Drive, HVDC, 120VAC)
  12. Screw the new Power Supply with the bracket into the base of the Table.

Finalization

  1. Power up the Table from the Service Switch Panel.
  2. Verify that the Table up/down and in/out functions are operating normally.
  3. Turn off all 3 switches (Axial Drive, HVDC, 120VAC), and re-install the Table covers.