Quote Originally Posted by teiteit View Post
Hi, after reading the thread only one person has tried a 550 to 220 conversion but failed. ................
I don't think you can safely draw that conclusion. There are undoubtedly many who have succeeded but haven't posted for help because they didn't need any.

The principles set out in Post #1 are fundamentally sound, and quite safe because that method uses the original boot.bin of 5x0 fw retaining the HWID of 0723. In fact, because the two devices are practically identical in hardware and share the same [Only registered and activated users can see links. ] of 105-01364-00, it is almost certainly possible [but inherently more risky] to flash the full zumo 2x0 fw to a nuvi 5x0.

All nuvi 5x0 are the same identical hardware, 500 or 510 or 550 naming only indicates the regional pre-loaded mapping. nuvi 5x0 doesn't have a BT module so can't fully convert to zumo in that respect. Some other points which I don't think are mentioned in Post #1:

  1. If it's present, remove the file GUPDATE.GCD from the nuvi's Garmin folder before you start any conversion flashing [it's actually not in a hidden .System folder of 5x0 and neither are the maps, that's only for more modern devices. nuvi 5x0 has all that in Garmin folder]. If you don't remove it that file may flash the unit back to full nuvi 5x0 or even cause it to 'soft-brick' under some circumstances. If it's not there, don't panic because it's not always on the unit.
  2. Do a NV Backup, both before conversion and after conversion: [Only registered and activated users can see links. ]. This could save your unit, so do it even if you're not intending to convert.
  3. Clear user data by hard reset both before and after conversion [hold lower RH cnr of screen powering on]. Backup favourites first if you want to restore them as it will clear all history.
  4. Use the latest available version of fw to do the conversion.
  5. If using the original nuvi 5x0 boot bin, name the rgn file as 072301000xxx.rgn where xxx is your new firmware version. e.g. if using v3.00 zumo fw, best name it 072301000300.rgn after ticking the HWID and SW Version of 'Overrides' in the top section of RGN_Tool to '0723' and '300' respectively. If flashing the full fw of zumo220, you'll have to force it to flash using a name such as 'out.rgn' or just leave a zero out of '01000' [it's that sequence which tells updater.exe to check the HWID match of the RGN file and the unit itself]. Any naming of the rgn other than <HWID>01000<SWV> will force the flash so be careful with that. The risk of bricking is much lower with original 5x0 boot.bin and HWID 0723 for the inexperienced that far out-weighs the inconvenience of doing fw updates manually. Using the full zumo 220The decision and risk is yours alone either way, only you can gauge your experience and risk tolerance level and all fw flashing carries some risk.