3-48
   Compaq Professional Workstation AP550 Maintenance and Service Guide
Power Supply
To remove the power supply (128399-001):
 1. Perform the steps in the “Service Preparations” section as previously shown.
CAUTION:
  Before removing the workstation access panel, ensure that the workstation is
turned off, all cables are disconnected from the back of the workstation, and the power cord is
disconnected from the grounded AC outlet.
 2. Remove the workstation access panel.
 3. Disconnect all power cables from the mass storage devices and the system board.