Power Functions Troubleshooting

Power Functions are retired electric building components for LEGO® sets. They’re most often used in LEGO Technic™ and Creator sets. We’ve got some tips for you. 

Battery box 

We’ve found that alkaline batteries work best. Batteries with a longer nub on the positive end work better than batteries with a shorter one. They’ll connect better to the terminals in the battery boxes. 
 
The more Power Functions being used, the shorter the life of the batteries will be. If it’s important to you to have a longer battery life, like in a train display, it may be best to keep the Power Functions used to a minimum.  

With fresh batteries, when the battery box turns on, the light should be green. 

Checking lights and motors 

Power Function lights should work when connected through the dark grey connector at the end of their wire, and not the black 2x2 brick in the middle. 

If you’re checking a servo motor, it’s also important to set it into ‘Zero-Position’ before putting it in. To do this, make sure that the axle in the servo motor is neither turned to the right or the left. The axle should line up with the small hatch marks on the ring around the hole for the axle.