Computer After 1 Year Will Not Turn On When Pushing the Power Button?

[StormBrew]

Hello, I recently encountered a strange issue with my PC which I built roughly a year and a half ago. The system had been running fine with no issues since then, but for whatever reason, the computer will randomly not start up. I can tell the components are working fine, as the computer will start up if I unplug everything and replug my components. I doubt the issue is cooling related, as both my CPU and GPU stay between 30-60 degrees Celsius from idle to load. Could the issue possibly be with the actual case power button? Or is the issue a greater problem then it seems? My current specs are listed below:
PCPartPicker part list / Price breakdown by merchant

CPU: Intel Core i7-5820K 3.3GHz 6-Core Processor (Purchased For $0.00)
CPU Cooler: NZXT Kraken X61 106.1 CFM Liquid CPU Cooler (Purchased For $0.00)
Motherboard: Gigabyte GA-X99-Gaming 5P EATX LGA2011-3 Motherboard (Purchased For $0.00)
Memory: Kingston HyperX Fury Black 16GB (2 x 8GB) DDR4-2133 Memory (Purchased For $0.00)
Storage: PNY XLR8 120GB 2.5" Solid State Drive (Purchased For $0.00)
Storage: Western Digital Caviar Blue 1TB 3.5" 7200RPM Internal Hard Drive (Purchased For $0.00)
Video Card: MSI GeForce GTX 980 4GB Twin Frozr Video Card (Purchased For $0.00)
Case: Thermaltake Core V51 ATX Mid Tower Case (Purchased For $0.00)
Power Supply: EVGA 1050W 80+ Gold Certified Fully-Modular ATX Power Supply (Purchased For $0.00)
Wireless Network Adapter: TP-Link TL-WDN4800 PCI-Express x1 802.11a/b/g/n Wi-Fi Adapter (Purchased For $0.00)
Total: $0.00
Prices include shipping, taxes, and discounts when available
Generated by PCPartPicker 2016-11-07 22:11 EST-0500

 

[StormBrew]

Update: So my computer turned on again this morning, but now it has the same issue, no power on. I legitimately have no idea what's going on, can I please get some help?

 

[AppleGwava]

Try replacing the cmos battery,this is kinda weird