Hi - Our drops targets did that once when we accidentally bent the lever on the ball kickout (i.e., the solenoid which pushes the ball out to the plunger). The playing surface wasn't pushed far enough toward the back box when we lowered it and the lever and coil got scraped on the lockdown lever bracket. The drops targets cycled repeatedly as the sensors watched for a ball to move across the switches in the ball lane at the bottom of the outlane. Once we repaired the lever, things got better.