Do not disconnect power or the USB cable during the update. Interrupting the process can brick your charger, turning it into a paperweight.
Before we plug in any USB cables, let's address the skeptical voice in every RC hobbyist's head: "If it ain't broke, don't fix it." While that mantra works for mechanical parts, it is dangerous for smart charging equipment. Here is why you should keep your T240 Duo up to date: Htrc T240 Duo Firmware Update
To help clarify any specific issues you are running into, let me know: What is your computer running? Do not disconnect power or the USB cable during the update
Use a USB-C cable to connect the charger's "PC Link" port to your Windows PC. Here is why you should keep your T240
Ensure no background software is interfering with the USB ports and try running the update tool again.
