[SOLVED] Upgraded PC won't start up

[aj7286]

I upgraded my CPU, GPU and Motherboard and the motherboard LED flickers on when I flick the power supply switch but the PC doesn't start up. When I press the case power button the GPU fan briefly spins and the case LEDs flicker but both turn off again just like the motherboard. I've checked the CPU pins, the motherboard standoffs, the ram sticks, the CPU and Motherboard power cables and it still doesn't work properly. Does it sound like a CPU issue or something else?
CPU - AMD Ryzen 5 2600
Motherboard - Gigabyte B450 Aorus Elite (AM4)
GPU - Gigabyte Geforce Gtx 1070 ti
RAM - Adata XPG 2 x 8gb DDR4
SSD - Adata 480GB
HDD - Seagate 2TB 7200RPM
PSU - FSP Aurum CM 750W
Case - NZXT H440

 

[Supernova1138]

You may want to pull the motherboard out of the case and try booting it sitting on a cardboard box. You might have something in your case causing a short. You may also want to check your front panel cabling. If that's incorrect, you may have the power button not working at all, or having it constantly tripping the reset.