Can anyone tell me what it means when the status LED on a 2006 Mac Pro flashes constantly at power-on? I have a copy of the 2006 Mac Pro service manual, and it only explains a single flash and triple flash. Here's the situation. I inherited a 2006 Mac Pro that was fully functional except the front panel USB ports. I purchased a replacement front panel board from a parts dealer, and installed it in the Mac Pro using the service manual directions ( I'm an electronics technician). Everything worked fine after the installation. The front panel board was slightly misaligned relative to the case, and it made it difficult to easily insert a flash drive. I opened up the machine, loosened the mounting screws, and realigned the board (no cables were disconnected). When trying to restart the machine, all I get now is a constantly flashing status LED. I completely disassembled the machine and ensured that all cables are properly connected and nothing is shorted, but it didn't help. I can't find anything in the service manual or the Apple web site that defines what the constant flashing of the LED is intended to mean. Any ideas are welcome, thanks.