Computuer Making Strange Noises

[Daddy_Ben_Ben]

I built a computer about idk 4 months ago or so. It's got one old part, the hard drive, the rest are new.
Here's the list-
Evga 750ti
Evga 500watt 80+ psu
AMD Fx 6300
ASUS M5A 78L-M USB3
At first I had had the system in an old case from like 2003 (Brothers old case) that supported one 90mm rear exahust. The computer would make strange beeping noises that ranged in length, like an eeeeeeeeeeeeeeeeee sound, sometimes would not stop. Thinking it was overheating I switched cases, it's now in the Phanteks Eclipse Series P400. The strange beeping accourd again this time while browsing the interenet. Any idea what it could be? I feel like its too low pitch to be a PSU coil whine.

 

[Tolis_GR]

Open the case and try to isolate the noise. It could be anything, and likely coming from a dying hdd. Hdd's would make cranking sounds right before they die, so you should better back up any important files on the first place if any

 

[Daddy_Ben_Ben]

Open the case and try to isolate the noise. It could be anything, and likely coming from a dying hdd. Hdd's would make cranking sounds right before they die, so you should better back up any important files on the first place if any

well it's not really a cranking noise, it's more as if someone was putting a cord over a fan kind of noise, but i've checked all my fans and there isn't one