Serval0079

Hello all. First of all, sorry for my bad English, it's not my mother tongue. I have since November 2015 a MSI GT70 2PE (MS-1763), but this last July (2016) the fan died and i give it to a little computer repair service next to my town. I take it back in September (it take long to replace the fan because holidays) but two weeks later, the new fan began to malfunction too. The fan start normally, but after some second it began to run very strongly then stop, and then began again to run strongly and stop again and never stop this cycle. The sound is hardly bearable and the temperature rise too much. I gave it back to the same computer repair service but they take several months to try several methods just to give up and give me my laptop back with no issue resolved, just saying the motherboard died too. I then send it to the MSI After Sales Service in Poland, with the warranty exceeded, and again a deception : they don't have spare part for my computer and send it back to me. So, I don't know what to do. I don't even know if I really need to replace the motherboard or where i can find a reliable seller online.