I'v just bought Buffalo's external hard drive about three months ago, the problem came out about two months ago when i tried to transfer some files, and the transfer rate suddenly decreasing significantly from 30mbps to less than 1mbps in less than 5 seconds. it happens until now either turboUSB is on or off. please help me... my buffalo's model: HD-PV640U2

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Both devices must have USB 3.0 capability to enjoy the high transfer speed that 3.0 has to offer. Check the other device (not the Buffalo) as see if it has USB 3.0 support.
First, make sure the firmware for the external and the source device are up to date. Next, try swapping the cable.
If that doesn't work, check the source and target hard drives to symptoms of failure. The transfer speed will be slow if one of the drives is failing. The manufacturer of the drive should have free diagnostic tools on their website. If not try WD Lifeguard Diagnostics or Seagate Seatools. If you are running Linux, go with smartmontools.
If the drives are healthy and if 3.0 is supported on both devices check the transfer speed with different files. Transferring one large file is faster than transferring a lot of small files.
If all else fails call Buffalo and request a replacement.

The file is too large meaning that the size of that SINGLE file is too large. Your hard disk is probably formatted to a FAT32 file system, this results in a maximum of 4gb PER FILE maximum transfer. What you could do is archive it into a few parts using winrar and then moving it onto the disk, and when you need the file just extract the archive. Your problem isn't the total free space, it's the size of that file chunk.

If it behaves like this for multiple computers with multiple operating systems, I would think that the problem is with the hard drive or with how the files were stored. I would recommend trying a free recovery utility:
http://www.piriform.com/recuva

If this does not work, there are professionals who can do this service for you however it is generally expensive.
As a last ditch effort, boot your computer from a free Ubuntu CD (http://www.ubuntu.com/download/ubuntu/download) and see if it recognizes your files.

schonie:

From reading on the Buffalo web forum just now, you need to try using a different USB cable. If that doesn't work, try using the device on a different computer. If it continues to not work, then the device has failed in some way.

Contact Buffalo as soon as possible to request an RMA to replace the drive (http://www.buffalotech.com/contact/). Information on Buffalo warranties are available here: (http://www.buffalotech.com/support/warranty/)

If you have data on the drive that you absolutely have to have, then you may want to consider sending the drive to a data recovery service like DriveSavers. There are many drive recovery companies available. I not DriveSavers as an example and because I have experience with them.
http://www.drivesaversdatarecovery.com/

Thanks for using FixYa.

I can not format a transcend external hard disk.Please Solution it problem.

We understand that your problem is:
hello i was using my buffalo ministation 320 gb external hard drive about a week ago, it was working fine but I left it on my bed when I was done. About 2 days later I went to change my bed sheets and the external hard drive feel on the floor. Now when I connect it to my computer it makes a connected sound but it does not show up on my computer but it is recognized when I safely disconnect it from my computer. I tried it on my laptop, it installs but its the same, it is not detected under my computer so therefore I am not able to access my files. Please tell me what I can do to retrieve my data. Thank you.

Check the usb port function in the computer bios settings and be sure that it is set to yes. Connect properly your external drive. If it has two wire usb connections, use both to obtain the maximum power that will be need by your drive.

It is probable that since the transfer did not complete, the data on the external drive will be corrupt.

Uninstall the external drive then reinstall and format the ext drive.

You should then be able to begin the data transfer process again.

It just sounds like bad luck that your pc froze mid transfer.
When you try again, do not use the pc for any other uses until the transfer has completed.

Regards and let me know if this works for you.

plz try to format the drive before transfer....