@jaydingo
Sometimes when you format using the built-in windows tool or some 3rd party softs the result is not entirely acceptable to garmin's OS. It especially dislikes formats done in MacOS. Using [Only registered and activated users can see links. ] with the settings suggested in initial post there seems to always work fine. If the other suggestions in the post above don't solve your problem then you may need to load [Only registered and activated users can see links. ] to re-enable Mass Storage Mode, copy any available files and folders from it, then format as i've suggested. Read this too, much is the same with 'bricked' outdoor devices as with nuvi models: [Only registered and activated users can see links. ].