Take the clock out, carefully bend back the tabs that hold the rear housing on it, then spray all the gears inside with WD-40 and it is almost guaranteed to start working again. You will have to repeat that process every couple of years to keep it working. You may also have to carefully clean the points in it to (they are what cocks it back every two minutes). Best way to clean them is to use a really small file. Be very careful doing this though because everthing in that clock is very delicate and if you bend or damage anything in there, it will stop working and at that point is not fixable--I know this from experience!