I know you have good Garmin knowledge Fa_Piter so likely now understand why your previous attempt to flash the V7.9's dumped 5 & 14 regions failed, however to explain more for others, region 5 is a sensitive region as it's the bootloader and if it becomes corrupted the device might never boot again and be 'dead'. To some extent rgn5 might be protected against direct flashing, depending on device. Also it may be impossible to directly flash it anyway as when boot.bin/Ldr.bin (note: despite the 'boot' reference, boot.bin is the ramloader) is being executed it's being flashed to a virtual region, region 12 (0x0C), which in turn flashes the bootloader to region 5 along with the x-loader to region 43. That's done entirely on the device. So you can see it may be problematic to try directly flashing rgn5 when rgn12 is also flashing it. If it's unprotected, a direct flash using a copied 5.bin alone as an RGN might succeed but may also hard-brick the device. Short story: Don't mess with region 5.