According to my dealer, they finally figured out the problem. Seems that the motherboard was feeding the wrong voltage to the RAM. Initially they were replacing the faulty motherboard/RAM with another faulty one.. After they had numerous cases of reoccuring fault, they finally figured out and made changes to production. Whether the issue is solved remains to be seen 
My dealer said that he is proactively contacting all his customers who has the old units to get the board replaced, because it will fail sooner or later..