Please try the following before you contact our support if one of your LittleBits doesn't work:

- Try wiping the connectors with a clean, soft cloth.
If that doesn't work at first, please carefully wipe all the connectors in the kit.
This will often resolve these problems.

- Try switching in fresh battery (if using the USB adapter, make sure you're plugged into an outlet). Certain modules draw more power than others, and switching to a better power source might help to solve the problem.

Once you've done this, try a test circuit to see if there is improvement:

- Put together Power > Input > Output.  See if the input bit affects the output bit like you would expect.   For instance - P1 power > i6 dimmer > o9 bargraph - when you turn the dimmer to the right, you should see the LEDs on the bargraph turn on from left to right.