Tank Assembly - Hologic QDR 4500 Technical Manual

6. Pull the XRC forward far enough for access to the FD (it is not necessary to remove the
XRC cables.
7. Remove the rear tank cover (covers the C-arm Interface board).
8. Unplug the 2 FD cables from the C-arm Interface board.
9. Remove 3 hex head screws (3/32" Allen screws).
10. Remove the FD by lifting it up (while tilting it slightly forward) and out.
Note: Early QDR 4500s have spacers on the standoffs that support the FD. If present, ensure
these are in place when re-installing the FD.
11. Replace the 3 hex head screws. Ensure that the curved spring washers are placed
(curved downward) so that the washer compresses when the screw is tightened.
12. Replace the cables.
13. Replace the screws in the XRC assembly.
14. Perform the X-Ray Beam Alignment procedure in the Alignment and Calibration
section of this manual.
15. Perform the Aperture Calibration procedure in the Alignment and Calibration section of
this manual.
16. Perform the A/D Gain Control Adjustment in the Alignment and Calibration section of
this manual.
17. Perform Beam Flattening in the Alignment and Calibration section of this manual.

Tank Assembly

To remove and replace the Tank Assembly refer to Figure 5-9, and Figure 5-10, and follow the
procedure below:
WARNING: Because of the weight of the tank (about 200lb), it requires 2 people to safely
remove and replace it.
1. Using the Motor Control Pad, move the table up and in as far as it will go, for easier
access.
2. Using SURVEY, move the Filter Drum (FD) aperture to 7.
3. Turn off the QDR 4500 computer and instrument power switches, and main power
circuit breaker.
4. Remove the lower C-arm cover by removing 2 Phillips screws and sliding it out from
the front. Also remove the bottom cover.
5. Remove the XRC (see procedure above).
6. Remove the FD (see procedure above).
WARNING: Before proceeding with this procedure, the C-arm must be locked in place (see
next step) or it will rotate when the L-brackets are removed.
Section 5 - Remove & Replace
5-21