# Problems reading usb flash drive



## redhalton (Feb 25, 2008)

Hi

I have a flash drive with jpeg images which I want to work on with my imac. Originally the flash drive images were saved on my windows machine, but I can't see where this would make any difference.

I plug the flash drive into my keyboard and my imac doesn't recognize it.

What can I do to access this drive.

Thanks.


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## eMacMan (Nov 27, 2006)

The keyboard USB port lacks sufficient power to operate the thumb drive. Plug it directly into the computer. 

I find it much easier to attach an USB extender cable to the computer and use that for thumb drives.


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## mclenaghan (Sep 27, 2002)

I have found that some thumb drives work and others do not. My 1 Gb Kingston drive does  but I have a couple of others that do not.  
Do some drives use less power?


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## MacGenius24 (Mar 4, 2008)

eMacMan said:


> The keyboard USB port lacks sufficient power to operate the thumb drive. Plug it directly into the computer.
> 
> I find it much easier to attach an USB extender cable to the computer and use that for thumb drives.


Yes he's right or Just buy a hub. Gets me thur the day.


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## bgw (Jan 8, 2008)

I've had a number of them fail in the past. I have one now that works under OS X but not with Windows XP on Boot Camp on the same machine. I know it isn't a formatting issue.... I suspect that some of the other posters are correct that it is a power issue.


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## EvanPitts (Mar 9, 2007)

Power can be a very real problem when connecting to a Mac keyboard, as it only supplies 100mA to the device - which is usually borderline on many devices. However, OSX will normally splash an Error Message telling you the port has insufficient power.

The other problem may be the formatting of the thumb drive. OSX will be able to handle it no problem if it is FAT32, but will bail out if it was formatted NTFS. As well, some thumb drives come with a preinstalled Rootkit or other software, which can cause hassles (not only with OSX, but with Windoze as well). It is best to format the thumb drive, to rid yourself of any potential problems before use.

The third problem is that, if you do not unmount the drive correctly from the Windoze system - that is, you just pull the drive out rather than going to the little icon at the bottom and Stopping the device - you may have corrupted the drive and made it unreadable. This is undeniably the leading cause of thumb drive failures.

Working under Windoze on Boot Camp on the same machine, but not doing OSX sounds like a problem with formats - so you can either reformat the drive as FAT32, or get a utility for OSX that can read NTFS...

So I would plug it in directly to either the port on the machine itself (unless it is a recent vintage MacBook, for which there is one High Power USB and the rest Low Power), or into a powered hub. If this clears it - your keyboard just can't handle the power output the thumb drive needs. Failing this, I would reformat the thumb drive as FAT32 (since yo are swaping files from Windoze to OSX), and pay particular attention when unmounting the drive before removing.


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## bryanc (Jan 16, 2004)

Actually, OS X can read NTFS natively, but the protocols for writing to NTFS partitions are proprietary and Apple is not licensed to use them.

So if you're failing to read, it's not the format of the stick, it's almost certainly power. Plug it into a powered hub or directly into one of the USB ports on your machine. If that doesn't fix the problem, it may be something more complex (such as 'live' software on the USB stick that makes it incompatible with Macs (SanDisc made some like this a while ago, but I think they've fixed the problem).

Cheers


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## krs (Mar 18, 2005)

A number of replies suggest reformatting the USB drive.
Not such a great idea since reformatting will wipe out the jpeg images stored on the drive.


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## rgray (Feb 15, 2005)

krs said:


> A number of replies suggest reformatting the USB drive.
> Not such a great idea since reformatting will wipe out the jpeg images stored on the drive.


So back the images off on to the PC which can read it which OP says he/she has - reformat the drive to something both can read (FAT32) - reload images from PC - load onto Mac... or am I missing something?


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## krs (Mar 18, 2005)

rgray said:


> So back the images off on to the PC which can read it which OP says he/she has - reformat the drive to something both can read (FAT32) - reload images from PC - load onto Mac... or am I missing something?


Yes, and no............

I really doubt it's an issue with the file system.
OS X can *read* both FAT32 and NTSF files natively.
The OP hasn't commented yet, but my guess is that it's a power issue.
Theoretically, the USB hub on a Mac keyboard (which the OP was using) should provide up to 100ma of current but I know that this is not necessarily true. Or maybe the USB stick takes more power.

I had a Logitech mouse once which was specified as requiring 100ma. Plugged directly into the keyboard it worked most of the time, but would often freeze for no apparent reason. After trying many different suggestions to resolve this, I read somewhere about a potential power issue - I then plugged the mouse directly into a USB port on the Mac and have never had a problem since.

I think the OP should try plugging the flash drive into a USB port on the Mac itself or into a powered USB hub before doing anything else.
If it still doesn't show up on the desktop - then try accessing it via disk utility - sometimes USB is a bit flaky launching automatically.


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## EvanPitts (Mar 9, 2007)

krs said:


> A number of replies suggest reformatting the USB drive.
> Not such a great idea since reformatting will wipe out the jpeg images stored on the drive.


The OP should have the originals already on the PC, or one would think.

As for formatting - I would highly recommend formatting any media first before doing anything. You just never know what lurks on the media. I've seen USB drives come with rootkits, with viruses, with trojans, etc., just like the external Seagate I bought that came with the same deritus. Formatting takes moments, starts everything fresh and clean, with no evils left lurking.

Unless a user has some real need, like transferring large files (something that is best not done with a slow thumb drive, but much better served by using a network approach, if available, or by burning a DVD, etc.), NTFS is the worst possible solution. There are some utilities that can write NTFS on alien systems, but they are spurious at best, and for the most part, NTFS is entirely unnecessary, a huge amount of overkill, and not very reliable in the long run.

FAT32 is the lowest common denominator, and unless a specific file grows larger than 2GB, it is the preferred format for devices that will have to go between PCs and Macs.


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## krs (Mar 18, 2005)

EvanPitts said:


> The OP should have the originals already on the PC, or one would think.


Yes - one would think........


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