Fix for "Unknown Device" when the iPod is connected

Question

After a few long nights, a few headaches, hours and hours of reading, thinking and many toasted sandwiches, I finally found the problem to my iPod not loading. Putting together information I had read here and at many other sites I had a brainwave... and sure enough it worked. I figure this may be helpful to many other iPod users, so... here I am posting my solution. Note though, this wont help all users, but I know I wasn’t alone with this issue, and this just might help someone.
I’ll list the issue I was having (this may help other people identify their issue to mine) was that the iPod failed to work on windows, and threw a fit when plugged in. Windows did too, iTunes would lock up and the iPod software failed to recognise that an iPod was connected. The iPod had worked on an older PCs before, but it failed to work on my new homebuilt PC. When I first connected the iPod it began to work, transferring and updating.. but then it unexpectedly disconnected the iPod.. and mentioned something to do with an I/O error, the iPod had to be disconnected and it also mentioned something to do with a timeout error and dataloss (or as it put it “Data has been destroyed”. That’s always a pleasant message to read). Suddenly, half the music on my iPod wouldn't play, it skipped songs until it found a song it would play... really annoying. I tried to format the iPod using the iPod software... buuut it told me that it wasn’t an iPod that was connected (Funny that... lol). After the first iPod crash, it would react differently when connected. It would once again pop up with the “Found new hardware” bubble, “Apple iPod...”, “Disk Drive...” ... then iTunes loads... then iTunes freezes... then the iPod disconnects 2 mins later, then iTunes unfreezes. THEN the next time the iPod is connected, it would say it was an “Unknown device”, and that it has “Malfunctioned”.
It seems that, oddly enough, my iPod (I own the 30gig iPod Photo) does not like USB 2.0... I’m thinking that it must not support some of the device commands the PC is sending to it... Weird though, because on other USB 2.0 PCs it worked fine. (I got the best results out of Dell PCs...). IF USB 2.0 is disabled and slows to USB 1.1 the iPod works a charm... jumped up without an issue in the world. To disable USB 2.0, jump into BIOS as your pc is in its POST stages... this being, when the PC is first turned on and presents a message such as “Press DEL to enter setup” (or something similar), do so. Then refer to your manual on how to disable USB 2.0, if possible. Apply the changes and reboot. Be sure not to mess around with other settings, it is very easy to mess up your computer if you change settings you are not familiar with.
Other solutions would be to run the iPod via Firewire... if you can get a cable. Run along to your local mac store and see if they have one in stock. I’ll get back on here to post if using Firewire solved the issue later.
Perhaps a motherboard BIOS upgrade, or newer drivers could resolve the issue. This may explain to some people why their iPod stopped working overnight after working fine for so long, maybe an update of the sort was installed. Apparently my motherboard already has an update, so I’ll test that sometime and post my results as I investigate further, but as for now I’m just happy my iPod is working, even if it is taking ages to transfer (25 gigs of music takes awhile over USB 1.1 lol...).
Also, I might add that my motherboard is an ASUS P5P800 with the Intel 865PE chipset. It could be an interesting pattern seeing which motherboards do not seem to be compatible with the iPod at USB 2.0 speeds.
As long as this post was I hope that someone gets some use out of it. I’ll post further findings as I investigate this matter further.
Happy iPodding!

Answer 1

hi Jazza!
the best explanation for this that i've seen is that there can be power drain problems in USB 2.0. drop below 500 mA running through the port and everything goes to pot. this may well explain why switching back to USB 1.1 sometimes works like a charm, and also explains why it's important to have the ipod plugged into a high powered USB port rather than a low power port.
i've seen a confirmed case of a USB connection going west after a scanner got plugged into the beast in question ... periodically i see other reports along these lines, too.
Roger Whiteley, "USB Device Not Recognized" #16, 04:18am Aug 3, 2005 CDT
love, b