Fitbit Charge 5 F39 Error Code Guide (Real-World Fix)

This is the official path, basically what Fitbit support will walk you through. Do it in this order, slow and clean.

1. Give it real power first

• Clip the Charge 5 firmly into the original charging cable.
• Plug the USB end into a solid wall adapter, not a flaky laptop port or hub.
• Let it sit at least 30 minutes. Low or unstable power during an update is how you get codes like F39.

2. Try a normal restart (if the menus still work)

• On the Charge 5, swipe down to Settings > Device Info > Restart Device.
• Tap Restart and wait for the Fitbit logo.
• If it boots clean and the error is gone, sync with the Fitbit app right away and check for pending firmware updates.

3. Force-reboot with the charge cable

• Keep the tracker on the charger.
• On the flat USB end of the Charge 5 cable there is a small button.
• Press that button 3 times within about 8 seconds, with a short pause between presses.
• Wait 10–15 seconds. You should see the Fitbit logo, then a normal boot if the firmware can recover.

4. Remove and re-add the device in the Fitbit app

• Open the Fitbit app on your phone.
• Go to the Today tab > your profile picture > tap your Charge 5.
• Scroll down and tap Remove This Device, confirm.
• Force close the Fitbit app and reboot your phone.
• Open the Fitbit app again, tap Set Up a Device, pick Charge 5, and walk through setup so it can push clean firmware back onto the tracker.

5. Full factory reset / clear user data

• On the tracker (if you can get into menus), go to Settings > Device Info > Clear User Data.
• Press and hold the on-screen confirmation for about 3 seconds until it vibrates.
• The screen should flash and reboot as if it is brand new.
• Now go back into the Fitbit app and set it up again like a new device.
• If you see F39 after a clear user data attempt, that’s the tracker telling you the wipe/firmware process failed.

6. Try a different phone just to rule Bluetooth out

• Install the Fitbit app on another compatible phone or tablet.
• Log in with the same Fitbit account.
• Try setting up the Charge 5 from scratch on this second device.
• If F39 still blocks setup, the problem is inside the tracker, not the phone.

7. When the manual runs out: talk to Fitbit

• F39 that survives all of the steps above usually means a bad memory chip or corrupted firmware that end users can’t re-flash.
• Fitbit’s own documentation basically ends in: restart, clear data, reinstall, then contact Fitbit Support.
• If you are in warranty, they normally swap the unit. Out of warranty, they may offer a discount on a replacement, but there is no official repair service for a Charge 5 mainboard.