weird rhythmic noise from PC

[raxprit]

I have an 8-year-old PC running on Windows 10.
Recently, it has been making strange, rhythmic noises. I have attached a video of the sound for reference.

I have disconnected all my HDDs except for the 1TB SSD C drive, and the noise is still present.
I am unsure if the sound is coming from the fan, GPU, C drive, or elsewhere. Could you please help me identify the source of the noise?

The specs of the PC are:
Intel(R) Core(TM) i7-6700K CPU @ 4.00GHz 4.00 GHz
NVIDIA GeForce GTX 1080
32GB RAM

Thank you all in advance!

Rakesh

 

[pcrepair]

Most time, Rhythmic noises often come from fans, especially if they're starting to fail or if there's an obstruction. You can try to identify which fan is causing the noise by stopping each fan momentarily with your finger (be gentle and careful) to see if the noise stops.