STEM Troubleshooting


In case small LED on your USB converter does not light up – here a few things you can check:

  • Are wires firmly and exactly touching the + / -  connection points on your panel? These points can be fragile, so make sure the copper tape is firmly secured, fused with the wire underneath.
  • Make sure wires are not crossing i.e the + / – wires don’t overlap and also not the copper tape that is securing them.
  • Make sure electrical tape firmly secures wires
  • And of course – make sure the circuit is correct –  always pairing negative with negative & positive with positive.
  • Is the light source strong enough? – hold the solar panel very closely and directly up to the light. Try holing the panel in different positions, turning it to capture maximum light.
  • Check the stability of your +/- wires connected to the USB.     
  • Ensure your solar panel is clean, free from dust and finger prints
  • Feel free to contact us if you can’t fix the issue


As in all things solar energy driven, the science is meant to work with a strong and natural light source. Solar powered devices operate under full sunlight.

Particularly phones require quite a bit of energy and the chance to test your charger may only be possible in some cases.
You can give it a go and try to power up a phone or small (5volt) USB device - have fun experimenting with different light settings!
But don’t be discouraged if you can’t get optimal conditions to power a phone. Your recipient child will have plenty of time to wait for a full sunny day, to make the science come alive and keep experimenting with the best conditions!

Tip: Different phone types require different energy inputs [e.g. iPhone is harder to power up than Android]