'''There are Some Common problems with solutions:'''
* '''Destroy the Garmin USB drivers'''
Again download USB driver from trusted place
* '''Not compatible with .NET Framework'''
If, you are using incompatible .NET framework then immediately update it with Framework.
* '''Make some mistakes while installing map on Garmin'''
Download Garmin Map Update from reliable place
* '''Hardware failures'''
Make sure, SD card set in proper place or not loose, and device batteries and motherboard are ok. Now conclusion that having hardware problems, immediately contact to manufacturer or retailer for replacement.