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Repairing Damaged GT3X+/ActiSleep+ File Systems

Last Updated: Jun 02, 2017 10:07AM CDT

Note: this guide ONLY applies to GT3X+ and ActiSleep+ accelerometers that have serial numbers beginning with NEO or MRA1 and have firmware version 2.5.0 or lower installed.

GT3X+/ActiSleep+ devices can sometimes experience file system corruption when they are not used properly. This could be caused by a read/write failure during initialization (e.g. the device is disconnected during the initialization process), outdated firmware, exposure to moisture, etc. Some indicators that the file system is damaged may include one of the following messages in ActiLife:

  • "Eprom.bin" file not being found
  • The status on the device grid may report "No Drive Letter Detected" when you connect your device
  • You may experience multiple Device Communication Errors when you connect the accelerometer

When this occurs, you may need to reformat the device. The purpose of this article is to step through this process.

Please note: this will destroy any data on the device. If you have data that you need to retrieve from the device, please follow the GT3X+ Data Recovery Wizard first. Once you have retrieved your data, follow this guide. For issues with our legacy devices (GT1M, GT3X, ActiTrainers, etc), please email ActiGraph Technical Support for assistance.

It is strongly suggested that you connect your device directly to your computer's USB port for this procedure, bypassing any USB Hubs. Also, DO NOT DISCONNECT your device until the format has completed. Doing so could permanently damage the NAND Flash, rendering the device inoperable. It would then need to be returned to ActiGraph for repair or replacement.

First, close ActiLife if you have it open. You will then need to download and install the GT3X+ Format Tool (you can find this attached below). Once downloaded, because of a recent Microsoft Security Update, we need to ensure that the installer has the correct permissions to install all of the required components. To do this, right-click on the file and choose "Properties". On the General tab, near the bottom of the window, you may see a heading that says "Security" with a button next to it that say "Unblock". It should look similar to this screenshot:




Click on the Unblock button and then click Apply and then Ok. If you do not see this button, the security update in question has not been installed and you may proceed with the next step of the installation.

You must have Local Administrative privileges to install the GT3X+ Formatter.

Run the installer and follow the prompts. Once the installer has completed, click finish and by default the Formatter should open automatically. If you unchecked the option to run the Formatter upon completion of the installation, there will be a newly created shortcut in your Start Menu. Connect the GT3X+ or ActiSleep+ that you wish to format. You will see the following window:




In the center portion of the window, you should see any GT3X+ or ActiSleep+ devices that are currently connected to your computer. Once your device has been detected by the formatting tool, to reformat the file system, click once on the device listed to select it and then click on the "Format NAND Flash" button as indicated by the picture above. This will rewrite the file system to the device. When the process is done, you will see a message that the format was completed. If you have multiple devices that you need to repair, it is suggested that you perform this procedure on them one at a time. Simply disconnect your device, connect the next once and click Reset List. You can also use the Identify function to blink the LED of the device that you have selected.

Once you have finished formatting all the problematic devices, close the formatting tool, open ActiLife, and reconnect your device. It should now appear in the device grid as shown in the following image:




Note that the device is now in Halt (or Reset) mode. To put the accelerometer back into normal operating mode, simply initialize it as you normally would. For assistance with the initialization process, please refer to the ActiLife 6 Product Manual.

Please note: Using this tool will clear any Bad Block and Wear Leveling information from the NAND flash on the device and as such, is only intended to be used in the event of an issue with the device. Formatting the file system frequently (for example, after every use) will drastically reduce the life expectancy of the device's on board memory and introduces the possibility of the device trying to write information to a bad sector which can result in corrupt or unrecoverable data. It is VERY strongly recommended to only use this tool if you experience any of the circumstances mentioned at the beginning of this article or on the recommendation of ActiGraph Technical Support.

If you need any further assistance, please go to our support portal at From there, you can view many helpful FAQ's and Troubleshooting Articles; log in to check any existing Support Requests; or create a new Support Ticket if you are unable to find a solution. You can also email us at or give us a call at (877) 497-6996, Monday through Friday, 8 am to 5 pm CST.

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