You should be cautious doing software manipulation without advanced knowledge as you can easily brick the device permanently. For the present i suggest you restore the device as DS 61 with the original firmware flashed as an RGN file in preboot using Updater.exe and then assess whether to make a conversion. Before attempting a conversion again we'd need to know what you did to brick it before.
Direct dl from Garmin of GCD file:
Code:
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Convert the downloaded GCD file to an RGN file using RGN_Tool then flash with Updater.exe. Find those two files behind spoiler below:
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