Hello.

Try removing and reinserting the battery and try again.

Hope this helps.

Remove the battery for a minute or so and then reinsert it and power on.

Hi there,

Well first of all you can try to reset your GPS -
 Resetting the GPS -

The GPS reset function is helpful when the device doesn°øt
recognize your current location properly. If the device doesn°øt
recognize the current location for a while, please try the
following procedure before returning it to the retailer.
Park your vehicle at a safe place free of
obstructions
Select the Setting on the Home Screen.
Select the GPS Reset icon.
Tap the GPS Reset icon.
Allow up to 5 minutes for the Finedrive 400 to
locate a GPS signal
Contact Technical Support if your current position
is repeatedly not detectable
Note : If the GPS resetting is done while driving, it will take
much longer to receive a signal.

The above method is a soft method of resetting, you can try a hard reset just remove all the connections/battery from the gps and leave it for 2 hours and check again if it works. Post comments if further you have the same problem.

Good Luck!!

Thanks