Issue that I believe is the PSU

###Troubleshooting Help:

Hi Reddit - I am almost certain I need to replace my PSU. Please let me know if there is something I can try that I haven't already in terms of actually getting to the boot phase. I have tried replacing the power cable, trying a new socket and removing parts to reduce the load on the PSU but it still won't start (further description below). If it is pointless and I have to replace the part: What is a budget part that would still be able to support the build and be compatible with the motherboard?

Thanks a lot!

**What is your parts list? [Link to PCPartpicker build from 3 years ago](https://pcpartpicker.com/user/SamiRHGB/saved/#view=nwyPxr)**

* CPU: Intel - Core i5-4460 3.2 GHz Quad-Core Processor

* Motherboard: ASRock - H97M PRO4 Micro ATX LGA1150 Motherboard

* SSD: Samsung - 850 EVO-Series 250 GB 2.5"

* GPU: EVGA - GeForce GTX 980 Ti 6 GB Superclocked+ ACX 2.0+ Video Card

* **PSU: EVGA SuperNOVA NEX 750 W 80+ Bronze Certified Semi-modular ATX Power Supply**

**Describe your problem. List any error messages and symptoms. Be descriptive.**

I press the power button, the fans spin for about 0.5 seconds before the whole thing shuts down. This repeats indefinitely unless I stop the power supply to the PC.

**List anything you've done in attempt to diagnose or fix the problem.**

I have taken the PC entirely apart, trying to start it with only the Motherboard, SSD and RAM connected, the PC still wont start. I am 99% sure it is a PSU problem and that I will have to replace it. I have rehoused all of my cabling and tested the parts connected individually - therefore I don't think it is the motherboard or the CPU, it isn't even getting to a (failed) BIOS, just restarting after 0.5 seconds.