My Mac Pro late 2013 keeps shutting down

Hi Guys,

Hopefully someone can advise me.

I have a Mac Pro late 2013. Recently it was repaired by Storm Front (authorised repair centre ) for what turned out to be a faulty i/o board as Thunderbolt ports werent working.

But ever since I’ve had it back it literally just turns itself off after intamitantly.

I never had this problem before the repair. It’s been back to the repair centre again last week and they did manage to recreate the problem once, but they reseated the ssd and then stress tested for 2 days and was fine. I had it back and all was good for a day and then yesterday in the middle of a paid studio session happened again... and again...

and again. So I’ve Booked another genius appointment but wondering if anybody had a clue to what it might be. I’m at my witts end. I’ve tried to do a fresh install of Mavericks as advised by the engineer.... which was a mistake as now it keeps powering down half way through install. 😢