• Topic ID: id_12374919
  • Version: 1.5
  • Date: Jul 5, 2019 6:08:29 PM

PAC Replacement

Prerequisites

Table 1 Personnel requirements
Required persons Preliminary requirements Procedure Finalization
1 Not Applicable 30 minutes 30 minutes
Table 2 Tools and test equipment
Item Quantity Effectivity Part number Manufacturer
Non-magnetic Service Tool Kit 1 -

5112581

 -
Table 3 Replacement parts
Item Quantity Effectivity Part number Manufacturer
PAC-2B or PAC-5 FRU 1 -

See FRU manual

 -
Table 4 Safety
  • danger
  • Electrocution Hazard!
  • Dangerous Voltages are Present around the Magnet Enclosure and Rear Pedestal electronics.
  • Perform LOTO on the magnet enclosure. See the MR Service Safety Manual, PN 5452735.

Overview

This procedure explains replacement of the Physiological Acquisition Controller (PAC) assembly. Discovery systems may have either a PAC-2B or a PAC-5. See the appropriate section of this procedure for replacement instructions.

PAC-5 units are backward compatible with PAC-2B. There is no impact with PAC hardware configuration in Guided Install.

Removal of PAC-2B or PAC-5

Procedure

  1. Perform LOTO on the RF amplifier and PEN cabinet. See the MR Service Safety Manual, PN 5452735.
  2. Locate the PAC under the left side of the magnet enclosure, mounted to a movable sled with four pieces of Velcro.

    Figure 1. Location of PAC

  3. Remove the left skirt covers and expose the tray that holds the PAC and SRI. See Skirt Cover Removal and Installation.

    Figure 2. PAC Tray

  4. Disconnect the cables attached to the PAC.
  5. Remove the two hex-head screws that hold the tray in place (one on each slide), and slide the tray out for access to the PAC.

    Figure 3. Screw Location

  6. Because the Velcro holds the PAC to the tray, lift the PAC off the tray and remove it.

Installation of New PAC-2B or PAC-5

Procedure

    Notice Image
    • notice
    • If replacing a PAC-2B with a PAC-5, use existing cables. Do not order a PAC-5 Y cable.
  1. Place the four pieces of Velcro from the FRU kit onto the SRI/PAC sled where the new PAC will be installed.
  2. Attach the remaining four Velcro pieces onto the PAC. Secure the PAC to the sled by mating all eight Velcro pieces.
  3. Attach all previously removed cables to the replacement PAC.
  4. Slide the tray with the PAC attached into its original position. Reinsert and tighten the hex-head screws.
  5. Replace all previously removed covers.
  6. Remove LOTO and restore power to the system. See the MR Service Safety Manual, PN 5452735.

Finalization

Procedure

  1. Perform a TPS Reset.
  2. Confirm that the reported problem has been solved by running PAC diagnostics. In Service Methods, instructions for these diagnostics can be found in Troubleshooting > Diagnostics > Hardware Location > Magnet Room > PAC Diagnostic Tests.
  3. Perform a Check Scan.