Orange flashing light on rampage mobo

So, I just put in an old graphics card after I took my new one back to the store while I'm waiting on my newest one to arrive... The light above the sata cable, which according to the asus user guide is the HD light, is flashing orange. This only happened after I took out the first graphics card and put in this older one. The light flashes orange even with that old card out. If anyone has any ideas on what would be causing this or the solution to fix it I would appreciate it alot. The tech guy at asus had no idea. He seemed to think it was the older graphics card causing it. It is an Nvidia 7800gt which I had in my old rig, it's probably 3 years or so old but it works fine. Thanks in advance.

Look in your manual on page 2.2.3 it's the onboard HD_LED activitly light. I have the same board. I can not believe that the Asus tech did not know this! There's nothing wrong with the board, graphics card, or hard drive.