Hi, thank you for contacting JustAnswer.com. My name is Russell. I will do my best to provide the right answer to your question.
If the Garmin (or other?) device keeps turning Off, how soon after being turned On does that happen?
And how is the Garmin (or other brand of ?) device powered? on battery, or on AC Adapter, or on car adapter?
And does any message on its screen appear before it powers Off?
Please let me know, using the Reply To Expert function, and I will advise you as to what to do.
Then this is what you need to do, on your computer, with the Garmin device:
Simply download, install, and use Garmin Express.
and (if you have a Windows PC) click on the big blue Download button at center bottom of the page. (If you have an Apple, click on the nearby Download for Mac link.) And download Garmin Express' installer to your computer, save it, then double-click upon it to install Garmin Express.
Then start the program, Garmin Express. Then connect your Garmin device. Then use Garmin Express to update your device.
Let me know how that goes. Or if you have any difficulty with the process, ask me for guidance through it.
I don't think you should pay again for an update. (Nor have I asked you to.)
Does it behave any differently, when you unplug the car adapter, and then turn it On? please try this. And then let me know how it acts, that way.