Starting today, my HX750 has started to make a faint buzzing noise that I can only hear when arounda couple feet away from the back of the PSU. The psu is always making noise even with power off (switch still on) until i unplug it from the wall. i have tried sticking it into a different wall outlet and the buzzing is still there. I am just unsure as what where i should go from here. I am considering RMA.