Your AMD Ryzen 5/Intel i5 7600 has an iGPU on it, if you're able to get the system to POST/get to OS GUI with the iGPU then your PSU's unable to power all your components while a discrete GPU's populating the system.
As for your PSU suggestion, if you truly need to replace it, why aren't you undergoing an RMA if it's only 5 months old? Where are you located, what is your preferred site for purchase and what is your budget for a PSU purchase? Make and model of your case? In case there might be clearance limitations.