alpine pdr-m65

Hi my alpine rw12-d4 started making this noise shortly after I got it last June. If anyone has any idea what this noise is that would be great before I take it back under warranty.

Item(s) for Sale: Alpine PDR-M65 Item(s) Description/Condition: Brand new condition. Used maybe an hour total. Original manuals and paper work, no box. 450 watts @ 2 ohm , 600 watts @ 4 ohm. would be willing to trade for a 750 -1200 watt RMS stable at 1 ohm Price: $300 Shipping and...