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Unable to format Sandisk Extreme USB 3.0 to Mac OS Extended (HFS+)

I have a Sandisk Extreme USB 3.0 flash drive that is 64GB, it used to work properly when i bought it few months ago (formatted to Mac OS Extended [HFS+] file system). Then there was this one day when all out of a sudden it just stopped working properly, it wouldn't access the data when i plug it into my Macbook Pro, it just says that 'The disk you inserted was not readable by the computer' and the only choices were to initialise (brings up disk utility), ignore or eject. I tried to format it back to HFS+ (Mac OS Extended Journaled) but it always gets stuck halfway during 'partitioning' and the estimated time seems to always get longer and longer (i tried leaving it overnight for it to format but in the morning it was still stuck at the 'partitioning' process, and the estimated time has gone up to 7 hours! I tried formatting it to ExFAT and the formatting completed very quickly (within a minute or so) but the problem with this format is that it wouldn't remount (the computer cannot read it even though i plugged and unplugged it multiple times). I next tried to format it to MS-DOS (FAT 32) and this time it worked fine, it was able to remount itself properly after formatting. I am able to format it to ExFAT using a windows PC but the read and write times was horrible (on both macs and PCs). This was not the case before all of this went wrong. My external hard drive was also faulty (read error) but i managed to format it back to HFS+ without difficulty. Is there anything wrong with my computer or flash drive? Any help would be much appreciated, thank you in advance.

MacBook Pro with Retina display, OS X Mountain Lion

Posted on Apr 26, 2013 8:06 PM

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Unable to format Sandisk Extreme USB 3.0 to Mac OS Extended (HFS+)

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