PC is making a humming noise, how can I locate the source?

[Christopher Aubert]

So now almost every time I boot up the PC, I hear this humming noise coming from the PC. It used to do this before rarely, but now it's doing it extremely often. I found on a whim that if I pushed on the front of the case (pretty forcibly) then the humming would (potentially) stop. Sometimes it stopped entirely when I pushed on the case, now when I push on the front of the case, the humming just kinda goes away for like 10 seconds, but comes back.

Lastly, usually the humming is there, and then it just goes away at random, and doesn't happen for the rest of the day, usually in the morning when I boot up the PC. Here's a little image of my fan configuration: https://puu.sh/vsARV/cd1a3704b1.png
Specs are below:

PCPartPicker part list / Price breakdown by merchant

CPU: Intel Core i5-4440 3.1GHz Quad-Core Processor
CPU Cooler: ARCTIC Freezer 7 Pro Rev.2 45.0 CFM Fluid Dynamic Bearing CPU Cooler ($21.99 @ Amazon)
Motherboard: Gigabyte GA-B85M-DS3H Micro ATX LGA1150 Motherboard ($76.99 @ Amazon)
Memory: G.Skill Sniper Series 8GB (2 x 4GB) DDR3-2400 Memory ($66.63 @ Amazon)
Storage: Samsung 850 EVO-Series 250GB 2.5" Solid State Drive
Storage: Western Digital Caviar Blue 1TB 3.5" 7200RPM Internal Hard Drive ($49.99 @ Amazon)
Video Card: EVGA GeForce GTX 1060 6GB 6GB SC GAMING Video Card ($239.99 @ Amazon)
Case: Corsair 100R ATX Mid Tower Case ($47.99 @ Amazon)
Power Supply: Corsair Builder 430W 80+ Bronze Certified ATX Power Supply
Optical Drive: Asus DRW-24F1ST DVD/CD Writer ($18.69 @ Amazon)
Operating System: Microsoft Windows 10 Home OEM 64-bit ($92.99 @ Amazon)

 

[Achint2000]

Sounds like a loose component, like a fan, or something stuck in a fan. It can also be the CD/DVD reader trying to read the CD often. There are many possibilities.

I would try open the case's side window first and try to hear where that sound's coming from, it's quite simple.