Alienware Aurora r4 PSU beeping

So i have a beep sound coming from my power supply i really don't know what can cause it i've searched everywhere on the net

my pc works fine but i get a beep every once in a while sometimes i don't get it for a half hour and then the hole time its not only when i'm gaming since i've also heard it when i wasn't doing anything

no i didn't change anything on my computer's hardware recently

- its not because it hasn't enough power (i've tested it)

- cpu isn't overheating

- all fans are working

What could it be? i really need to fix it its annoying hearing that beep the hole time

the beep lasts for 1-2 seconds it isn't like the boot up beeps its less clear

i really need help with this one

Edit:

also no, its not a alienware bios code before you reply that

yes i'm sure it comes from the psu and there are no components behind it or anything so it can only be that

yes i've tried removing the psu and then reattaching the cables and putting them back in

yes i know a psu isn't suposed to make sounds