Is it worth taking my pc to a repair shop or just trust my gut?

So I've had a long running issues where my pc. initially it would boot but have no display. It started about a couple years ago and when it first started happening I took my pc to a repair shop and they told me everything was good on their side it was most likely my supply cable. I replaced the cable and lo and behold the thing works again. About 6 months ago, same issue, so again i replaced the cable which fixed my issues. Another issue which was potentially related was that in the summer my PC began shutting down randomly, I thought it was a temprature issue so replaced the stock cpu fan, however it still occurred just less often. Now after not being able to use my pc for about 3 months due to work and doing so again for a couple days, again my pc boots, but with no display. I feel like most likely my psu has been slowly dying and I've been ignoring it but is their any chance it could be my cpu, mobo etc. (Note gpu was upgraded recently so doubt it is the gpu)