if it is not the battery then it sounds to me as if the magnets that make the shutter work are not doing their job properly, or if it has a capacitor that works the shutter magnets, maybe that. You can not fix that yourself. This is something that might not show up on a quick look-over by anyone, so it is not necessarily the fault of the inspector.
so, may be time to find out if that guarantee is any good. The xe7 is a nice camera, find a good one. Here's one: http://www.keh.com/camera/Minolta-Ma...105007170?r=FE
but to be fair, put a brand new battery in it first.