I had to reformat my SD Micro card

[Wowbagger]

I'd had some problems with the Garmin for a while, when transferring files via the USB port. They would start transferring and then would stop part-way through. Very frustrating. I thought, but I was by no means sure, that it might have been down to the USB cable not being plugged in properly

Then last week I decided to download the Andy Gates maps again because my GMAPSUPP.IMG was decidedly old, but I couldn't. I'd plug the card into the reader and the machine wouldn't recognise it - at least, it showed no sign of realising that it was plugged in but it complained when I unplugged it. Dez thinks that might have been what corrupted it.

It required FAT16 formatting, which was a pain because the Mac I'm using, running OS X version 10.6.4, wouldn't format anything more primitive than FAT32. I had to make the machine run Windoze instead, which was also a pain because it's about 5 years since I used it and I'd forgotten what to do.

It's working again now.

[Manotea]

I've had this twice with my 705 which is only a few months old. I am running the dreaded 3.2 (the version which was withdrawn) as I tried and failed to effect a downgrade. I cannot remember having to do this for the card in my Vista HCx.

[andygates]

That's odd, I had to too.

I can't see how a non-running file could do anything evil; maybe there's a wackiness in the Garmin file-handling that inefficiently thrashes the same bits, or something.  Still, a format took seconds and sorted it: I'd pegged it as just a grumpy card until you mentioned it, Wow.

Most strange.

[Kim]

I had to reformat the card I re-purposed for the Vista HCx when I got it, but at the time I assumed that was a FAT32/FAT16 issue.  Not had trouble with it since, touch wood.

[frankly frankie]

I use FAT32 and don't see any problems, using various Etrex C models and Dakota.

[andygates]

FWIW, I am scrupulous about keeping that comp clean of nasties. 

[frankly frankie]

maybe there's a wackiness in the Garmin file-handling that inefficiently thrashes the same bits, or something.  Still, a format took seconds and sorted it:

I should think if you load a big map file onto the card, then replace it periodically - you're rapidly going to get fragmentation building up.  As you say, formatting is quick and easy to do.