Netgear Nighthawk C7000 chirping noise

All,

I have had this refurbished NETGEAR Nighthawk Cable Modem WiFi Router Combo C7000 since about March of this year.  It just recently started to making a chirping noise.  There is a no rhyme or reason.  The only other time I have heard a simliar noise is when I had a portable hard drive crash and it make a chirping noise when you would plug it in to the USB.

I am think that I will execute the warranty I picked up from Amazon.

Any thoughts?!?

Thanks