Sorry to hear that @Stan_Halen , can’t offer advice without the details which is probably for the best coming from me.
If you are a DIY guy I’m sure you know the drill of whether it’s a BSD or no start issue, (dead drive, bad ram or power supply?) maybe even some power surges in your neighborhood?
I recently had some random BSD and finally ended up yanking one RAM card, the others still work because one socket on the MB was bad I guess.
All that’s easily fixed, of course it might be time for an upgrade . . . oooh, now that’s tempting!