I am not receiving any data transfer from the hard drive to the monitor. I cannot turn off the hard drive with the on off switch on the front of the unit. When I power down and power up the unit via unplugging and plugging back in the hard drive, I receive 3 beeps. Of the 4 lights on the back of the unit (A,B,C,D) only the C&D lights are lit green. The A&B lights are yellow. The people at DELL support had me re seat the memory card, and then replace it. Neither solution was the final resolution. Am I having a hard drive problem?