When I plug the power cord for my Garmin into the car, the display instantly is too dark to see anything. When the cord is removed and the Garmin is running on battery, the screen is fine. Shouldn't be Garmin work when plugged in???

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Make sure you have your time and time zone set to match your area. Also look in display settings to see if it is set to night mode versus auto adjust.

It could be a problem with the mini USB plug on the charger. If it doesn't go in far enough it will cause that problem. Try pushing it in further. If that doesn't work you'll need to get a Garmin power cord.

I would go to Tools....Settings...Display.... check your Color Mode is it check on Auto...Daytime or Nighttime pick one then press OK

On the Brightness press it to set it brighter or darker then press OK

Hi Louise. Carefully pry the frame off from around the screen. It is thin and delicate so work carefully and use your fingernail. Once you have that frame off you will see a reset button. with the unit on, push the reset button. This may solve your problem, in fact it probably will. But, if it does not, go to Garmin.com and see how to mail it in for a repair. J.

Dead pixels you can't do anything about without replacing the COLOR LCD TOUCH SCREEN. Which will probably cost as much as replacing the whole unit anyway.
As for shutting down while plugged in, that may be one of two things. Either the charging cord has gone bad (and they do go bad), or your not plugged into the lighter/charging port in your vehicle completely. Lastly, the charging cord for a Garmin GPS has a fuse in it, at the head that plugs into the charging port. Check it to see that it's not blown. Chances are it may be.

It has gone into "Mass Storage Mode" because it thinks it is connected to a computer. Are you using something other than the Garmin power cord such as a cell phone charger?

Are you using the garmin power cord or are you using an aftermarket cord? Some after market cords have usb plugs that although they plug right in to the power port on the unit, they tell the unit that you are updating the database. The unit displays only a picture of a computer connected to the unit and that's all it will do. Their is a way around this. Simply wait until the unit displays the about photo of the computer attached and then unplug the power cord from the unit. After the screen clears immediately replug in the power chord. This must be done quickly before anything appears on the screen. If you're too slow, simply repeat this step until you manage to replug the unit before anthing appears on the screen. Once plugged in as about the unit will operate normally on the external power source until you either turn it off or unplug it. Simple repeat above when ready to resume use.

Found out from Garmin Tech services how to reset the NUVI. Good to go.

Thanks.