Mac Pro (Mid 2012) shuts down ater 30 minutes

Hello, BabzB.. i’d either guess power supply problem or the smc + pram needs resetting.. Obviously, don’t take your Mid 2012 Mac to an Apple Store with Genius Bar, they can’t snd won’t help you ( mac pro 2012 too old) an AASP might??

anyways, there are a few Facebook Groups devoted to the classic Mac Pro ( from 2008-2012) .. I suggest you check ‘em out and ask your question there… i’d post a link to how to do it, but that is frowned upon here, just Google “how to reset SMC and zap PRAM on Intel Mac”. I usually fo the zap pram thing at least 3-4 times..then let go of all keys and let your Mac start up (.or not) normally.. there is also a mac pro technician guide available on those Facebook Groups, msybe go there.. if reset smc and zapping pram does nothing, might be time for a PSU swap/replacement… i won’t be telling you how to do that here.., anyways, BabzB, go there, get the guide follow it and ask your questions there

John B.. oh and replace the pram battery , it’s on the backplane under the graphics/video card.. it lasts about 5 years, a BR-2032 is official replacement, but CR-2032 will work fine..

When you start up your Mac again, you should get a notification that says, "Your Mac restarted because of a problem", and occasionally a report or a code.

if you have any of that information, please post it.