Do yo delite gupdate.gcd before flashing and do you use rgn tool when you try flash with 1104.1108.
1104 and 1108 is for MTK chipset for nuvi 12xx and 13xx series and if you dont use rgn tool you brick your nuvi.
Download latest webupdater 2.5.1 and try to update your nuvi if wont work You can try flash with this:
[Only registered and activated users can see links. ]
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