Two brand new OptiPlex 5000 SFF units will not power on and POST at all if the Dell Image Assist USB is plugged into any of the USB ports. I am not getting any LED codes, the units just fan on, LED breathes for a sec, then shuts off and tries again until the USB is unplugged. I can get to the BIOS if I unplug the USB drive but there does not appear to be any settings causing this. BIOS is version 1.5.1.