• Topic ID: id_16157908
  • Version: 2.0
  • Date: Apr 9, 2020 8:49:21 PM

Detector Heater Control Board Replacement

Prerequisites

Overview

The objective of this procedure is to replace failed Detector Heater Control board:

  • Remove Covers.

  • Tilt gantry back for easy access.

  • Replace part.

  • Verify correct functionality.

Procedure

  1. Move the table cradle to the home position, and raise the table to its highest elevation.
  2. Remove gantry right side cover, and turn OFF Axial Drive and HVDC switches on the Service Switch Panel.
  3. Remove the gantry top and rear covers.
  4. Tilt the gantry all the way back to 30 degrees.
    5. Notice Image
    • notice
    • Always turn OFF the HVDC before the 120 VAC. Turning OFF 120 VAC power before HVDC power can result in equipment damage.
  5. Turn off all 3 switches (Axial Drive, HVDC, 120VAC) on the Service Switch Panel.
  6. Rotate gantry until the DHCB assembly is within reach (12 O’clock).
  7. Lock the gantry in position, using the rotational lock.
  8. Remove connectors.
  9. Disconnect Center DAS chassis power harness.
  10. Remove the top two (2) 4 mm cap screws (one front, one back).
  11. Drop unit down, and swing out on lower pivot pins.
  12. Slip pivot pins on new DHCB assembly into their slots, and rotate assembly into place.
  13. Replace the top two (2) 4 mm cap screws. Torque to 2.4 N-m (20.4 lbs-in).
  14. Reconnect cabling.
    15. Notice Image
    • notice
    • Always turn ON the 120 VAC before the HVDC. Turning ON HVDC power before 120 VAC power can result in equipment damage.
  15. Reassemble the gantry covers and restore gantry power.

Finalization

  1. Allow Detector to warm up for 15 minutes. Monitor detector temperature during warm-up and ensure it stabilizes at 36 degrees.