Thanks for your kind help guys. I have already paid Bitmain to send it back to me. Now I will follow your advice and send it to someone who can fix it.
I am just disappointed with Bitmain.
Well, what did you expect? Like many other manufacturers they're trying to earn and save as much as they possibly can. You could also try to find a used hashboard on our local classifieds website or on ebay. Labor is very expensive these days, perhaps a second-hand unit selling for parts could be cheaper.