One of the units is powering on but then "freezes up" and will not power off.

One of the units is not powering on.

One of the units is powering down by itself.

The Timer is missing starts from the Wand.

The Timer is missing finishes, splits, or starts from the Photocell.

The Timer is starting by itself. (False starts)

The Timer is stopping before the skier passes through the finish. (False finishes)