The latest round has been for data recovery after the unit locks up and then will not boot at all.

clipped from my service ticket...
Hook up on workbench and boot to BartPE CD. Hard drive isn't recognized properly. Reseat SATA cable and power to hard drive. Try booting again, but CD doesn't see drive. Try booting normally, but system crashes. Download Sata drivers to floppy from Dell's website. Boot using drivers on diskette, but system takes a long time to come up. System still fails to run chkdsk and R-Studio on drive. Try Dell hard drive diagnostics, but they don't appear to run completely. Boot to PowerMax utility and receive error code dd69937b after read scan fails. Try recovering data using Windows XP CD with Service Pack 2. Boot to Ubuntu live CD, but receive errors. Download and create "Ultimate Boot CD" but all utilities fail to read drive. Pick up SATA adapter and return PC. Pull hard drive and hook up to another PC using SATA adapter. Drive fails to access, but does display a drive letter. Successfully kick off "chkdsk /f" and allow to run. Successfully access documents! Copy "My Documents" folder and Outlook data from problem hard drive to network server. Replace drive in PC and it boots to desktop without any trouble. Reboot to Dell diagnostic CD and hard drive scan reports numerous errors.