Thread: Garmin Zumo 550 Formatted By Mistake

God only knows how the service desk drone at Garmin expected you to add files from another zumo when you don't have Mass Storage Mode available.

The boot-loop problem will be because the format is not quite to the Garmin OS's liking. Firstly you need to load a Cure firmware which should restore Mass Storage Mode so you can access the internal storage, see here: [Only registered and activated users can see links. ]. You should still be able to access preboot mode to load cure firmware, just try first loading QuickCure3 which is very simple to use, look towards the base of initial post there. If necessary, make a full cure firmware as detailed in that post. Once you have MSM back, re-format it in FAT32 not with the Windows builtin tool but only using [Only registered and activated users can see links. ]. While connected to the PC add an empty root folder named Garmin and then safely disconnect from PC. It still won't boot but should stop bootlooping and now just stick on the logo screen (cure fw can't boot the device, it's only used to re-gain MSM), so now load original firmware in preboot and it should boot. Connect to GarminExpress to load available missing files and replace it's entitled detail map. You will still need a basemap, get V5.01 from here, name it gmapbmap.img only: [Only registered and activated users can see links. ]. Post if you're confused before proceeding. If still missing some files post with details and we can try to source them.

EDIT: This should help in more detail if you're lost following the above: [Only registered and activated users can see links. ]. Also if your zumo 550 doesn't enter preboot holding the UPPER LH corner, try holding the LOWER LH corner instead (that works for zumo 6xx series).