Most likely failing small can electrolytics on the main board, and if you open it and see any 4V rated caps change them out wherever you see them. That should cure the fault.
I have a Sony camera with the same symptoms, and as there are over 50 caps on that board I decided buying another was the best solution. I got the camera for free, and as the battery was dying and not available as a pattern part ( but now has 2 new cells from an old laptop pack siliconed in place) and is the cost of a new camera it will be torn down some time.