How did you convert it? There are 2 ways of doing that. Did you flash hybrid firmware [5x0 boot.bin combined with 2x0 fw_all.bin] or full original 2x0? The first retains 5x0 HWID of 0723 and is much safer and easier to 'unbrick' a unit, but if the 5x0 boot has trouble loading the zumo fw then it will stick at loading.
Bookmarks