Everything and anything can become subject when "lightening damage" is concerned. I suggest you pull AC plug at the psu next time(5min.), replug when ready for use, it should reboot again. Of course, it can be your HD as well. Otherwise, I normally suspect the mtrbd. is getting flaky and/or the start ckt. is kaput, no fix, but replace. Don't take anything for granted, test elsewhere and rebuild system.

tada -----Willy Happy