On the power contacts, there were immediately oxides with traces of mechanical stress (apparently, someone tried to clean them before me). The battery cover does not fit tightly, making it very difficult to catch a position when there is contact and lock the cover in that position. I cleaned the contacts with an eraser, I managed to twist the cover and catch the contact, at first the tool turned on and even showed something. But now, when it came to work, he did not turn on at all and again it is impossible to catch contact between the cover and the battery. I consider the need for such dances with a tambourine to be unacceptable for a new and not the cheapest instrument. I put a three with an eye to positive, in general, reviews - perhaps not lucky in my case.