workstation BSOD all year round

So I got this precision 3640 for my work as an independent contractor teaching CAD. It had some BIOS update problems and Dell suggested I get the motherboard replaced which happened 7 weeks ago. After that repair BSOD has been haunting me till today. The machine got inspected by the "advanced resolution center", again some new motherboard and the statement that they were "very proud to return my equipment in pristine condition". It crashed with the same diagnosis fresh out of the box. I have spent oh so many nights with the Whatsapp-support which didn't help at all. With remote they reinstalled the operating system, by now three times and want to replace things again, this time not through their own repair but externally. I am really tired about this. 

That external company is waiting for  the parts. I am getting tired about this.