If you’re a heavy Fitbit Flex user, you may have run into a problem where you can’t get it to charge when you connect it to the USB dongle. Lucky for you, there’s a simple solution you can try if your Fitbit Flex won’t charge. It could easily be caused by some corrosion on the metal contacts.
If your Fitbit looks like the image below, it definitely needs a cleaning and could be the reason you can’t get a good charge.
1) Use a Toothpick
The first step is to take a toothpick and clean out what you can. Use it on each of the 3 contacts on your Fitbit.
2) Toothbrush and Rubbing Alcohol
The next step is to take some rubbing alcohol and apply to the contacts. You can use an old toothbrush or some cotton balls. Avoid using a metal or wire brush. You can also use the same method to clean the contacts inside the USB charging dongle, just unplug it first.
3) Dry Off
The final step is to dry off the rubbing alcohol with a soft cloth.
That’s all there is to it. If you’re still having an issue and your Fitbit Flex won’t charge, you could try resetting it through the USB dongle, but cleaning it usually fixes the issue.