Computer Repair Job - Akasia, GP, 0182

I need my computer repaired. I originally thought it was a GPU problem because when I turned it on nothing was displaying. I sent the GPU away to wootware since it was still underwarentee but I was told that the gpu was working just fine. When I tried using the integrated gpu it still wasn't working

So I switched it on without the case and found the CPU and ram light were blinking. My diagnosis is that it's either a power supply or a motherboard problem.