I just got my new Antminer S2 5 days ago, and one of the boards is faulty it works for less than two hours and then stops.   Only way to get it to work is shut down the whole unit..   But pointless as less that 2 hours again its stopped. 
My Questions,   is it safe to leave the machine still running.
Is there any contact phone numbers or other emails address to contact Bitmain.  I was emailing a few days ago but since I sent them some pictures no replies?   Must be a holiday over there..

Next Question Can I purchase a new board from someone or somewhere,


Thanking you in advance