To begin troubleshooting a grandfather clock, note any irregularities in its behavior. If the pendulum does not swing, it may be because the clock hands are touching each other. Nudging the hour hand toward the dial or bending the minute hand outward slightly to clear it may fix the problem.
Check that the weights have been properly wound, as the clock will not work otherwise. Make sure that the grandfather clock is standing level and verify that the weights are on the right chain. Perform regular maintenance on the clock including winding the weights every seven days and oiling the movement every two years according to the manufacturer's instructions.