DFU Virtual USB disk unusable


I have a DSO Nano v3 with “Device Firmware Upgrade V3.26D”. The DFU Virutal USB disk functionality plain doesn’t work. The disk shows up, but as soon as you try to do anything, like open it in explorer or Finder (I tried it on my Mac and PC), the disk ejects itself or timesout. In rare instances when it stays usable long enough for me to copy a file, the file gets renamed to BLAH.err.

Is there a way to fix this, or is it just faulty? I have tried many usb cables, and have also tried switching USB ports. Nothing has helped.


That’s normal operation for the DFU (Device Firmware Upgrade). The only files that are meant to be copied to the drive while in DFU are .hex or .dfu files which contain firmware. Normally, you would copy a .dfu file, the nano will reset momentarily and then when it reboots the .dfu will change to .rdy, indicating that the upload was a valid.

Don’t know if you have the problem sorted out, but I thought I could maybe help someone with this as I had the same problem. I am using Mac, and the dfu-drive disappeared before I had a chance to copy the files. The same problem happened when I tried it on virtual Windows XP or Windows 8 in VMWare. Then I went to a Mac with Windows installed natively by bootcamp and it worked directly.

I’m having the same problem here. Can’t get the DFU USB drive stable enough to do anything. Tried a Windows 8.1 laptop and a Mac MINI… Any clues? And just saying “that’s normal” isn’t gonna cut it. For the life of me, I can’ see why this thing is shipped without the patched BenF firmware… Right now it’s cute, but it won’t be really useful till I can get some new firmware onto it.

To get more specific, under windows 8, the drive may show up for a moment, then the Windows Explorer goes to a scanning/waiting state, and pukes cause the drive can’t be found. The comings and goings cause a bunch of stuff to happen, and always trigger the anti-virus software… On the Mac, the drive comes and goes, and I get a lot of “Disk not ejected properly” notifications… Copy fails with error 43, item cannot be found…

This is very painful!

Edit… To make matters worse, I’m on firmware 4.11. Seems there is no “off” setting on the Ex Data channel, so the hint in this thread to get rid of the purple trace doesn’t work for me… Also, saves of the configuration appear to not take…

So, I dug up and ancient Thinkpad running XP and all is good. The windows box that wouldn’t work was a new Sony Vaio laptop with USB 3.0, and the MAC Mini was USB 2.0 running under Mavericks.

Anyway, after upgrading to the patched BenF firmware the device is so much more useful!

Hope my experience helps others get there little Nano running good!