I have a MK2S and for some reason it wont reach the set temp. It comes close but misses by 7 to 9 deg. Set for 150 it will reach 143 and cool down just a bit and then start to increase to 143 again cycle after cycle. No mater what Temp I set it to it wont quite reach the set temp always a bit lower. Hence; it wont print. Any ideas would be greatly appreciated.