No, the hardware was not affected. The problem is that Garmin devices are very sensitive to the format of the visible file system. Not all FAT formats are the same by any means and although with some device types it doesn't matter at all, for Garmin devices it can be crucial to have the exactly correct format. RMPrepUSB format as per that link's settings mimics the original factory settings used by Garmin.
If you've heard the English speaker's saying 'There's more than one way to skin a cat' [yuk!] it's worth remembering 'There's more than one way to format in FAT'. NEVER use a Mac for Garmin formatting it'll always be a problem and mostly Windows gets it wrong for most Garmin devices too.
Thread marked solved. Thanks for reporting back.
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