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Remove all trains from the track , unplug the wall pack, plug it back in and observe if the light, still blinks. If it does, disconnect the terminal track from the rest of the track, and power it up alone. If the light does not blink, add one section of track at a time until the red light blinks. The last one you install that causes the light to blink is bad. Return for exchange if it is new.

If the light blinks with the terminal track alone, the terminal track may be bad. Return for exchange if it is new.

Larry