After sync, iPod Resets and and says 'No Music'

You might want to check and see if the hard drive is OK. The iPod has internal diagnostics that can check this for you.

Reset your iPod by holding the center and menu buttons until the screen turns black. Immediately start holding down the center and previous button until the screen turns white and you see the diagnostic screen. Hit menu for manual test. Scroll down to IO (you can scroll using the wheel or the previous/next buttons) and hit the center button to select. Scroll to harddrive and select. Scroll to hdsmartdata and select. If you see more than a very small amount of retracts and reallocs (i.e. more than a half dozen or so), your hard drive is starting to fail. If not, the problem likely lies elsewhere.

Once you've tried that, you can leave the test by resetting the iPod a second time.

Hope this helps!

Shawn

Hi Shawn,
I am following your advice since my daughter's iPod, which is synced to an external HD is having the issue of looking like it is syncing, iTunes saying there is space taken up, iPod settings saying there is stuff there, but "No Music, and No Podcasts" show up. I've restored 3-4 times, etc. The sync bar progresses with updating files, sync is complete. But even though in iTunes it shows GB amounts for music and podcasts, and on the iPod itself when going to the settings shows 34 GB free on an 80 GB iPod. The iPod shows "No Music", etc.

For retracts: 182
For Reallocs: 11

Any clues? If the HD is failing, why would it store GBs of music files, yet in the Menu show as "no music"? Could this somehow be an issue with maybe a couple of files she put on her Macbook from a friend's iPod. There may have been stuff purchased from the iTunes store that won't copy to the iPod or something like that. A few files that are not "legal" in that way. Could that cause an issue?

Hi Jody,

I doubt that any music files, legal or not, would be causing the issues you're seeing. In my experience, iPods with hard drives that are starting to fail (which is what the number of retracts and reallocs on yours indicates) tend to behave unpredictably. Without having any actual knowledge of what's going on at the firmware level, my guess would be that the failing hard drive causes corruption to the iPod's file system, which causes the iPod's operating software to become confused and behave in an unpredictable manner. The only thing I can say with certainty, unfortunately, is that the problems will get worse over time, rather than better.

Shawn

Thanks for the reply Shawn. Is there some sort of hardware diagnostic (after all it IS an HD), that can be run to determine HD viability? What about running Disk Utility on it and treating it as an HD to be diagnosed and erased/restored?

The best hardware diagnostic you can run is the one you already did. SMART is a standard reporting interface that hard drives use to report their hardware status. Disk Utility won't be able to see the HD's status, since it's not directly hooked up to the computer (just indirectly via the iPod's firmware).

Generally, if SMART starts reporting errors, it means there's a hardware issue, which no amount of software trickery will solve. The only course of action at this point is to replace the hard drive before it fails. This is true whether the drive is connected to a computer, iPod, or some other type of device. The idea is that SMART gives you enough warning that you can back up your drive (if you haven't already) and replace it when you can, instead of it failing at some unplanned time.

In the case of an iPod, replacing a hard drive is difficult enough that Apple Stores will simply replace the entire iPod rather than just the hard drive. If yours is in warranty, and there's no physical damage, they will cover it. Otherwise, there'll be a repair charge (the exact charge depends on the iPod). You can make a Genius Bar appointment if you want to go that route. Otherwise, there are third party companies that will service iPods, including hard drive replacement, or you could get 10% off a new iPod at any Apple Store by recycling the old one, working or not.

Shawn

Shawn, thanks for the additional explanation of the SMART status. I think you are right, this is probably imminent HD failure. However I have cracked open 3 iPods and replaced parts before, (HD, headphone jack assembly, etc.) and it really isn't too hard. Kind of fun actually. So I will check the cost of a replacement HD, against the cost of a new one and go from there.

Thanks for the detailed explanation, it was the best diagnostic yet!

I also am having trouble syncing, but with a 120GB Classic, not a 160GB. I did the test with SMART and got this:

Retracts: 76
Reallocs: 1608

Those numbers are really high, which I guess means the HD is failing. The only thing is, I just bought this iPod last June and don't use it a ridiculous amount (It only has 53 power on hours.)

Anyone care to explain?

Are you getting the same message after syncing - "no music", etc.? When you say you are having trouble syncing, could you detail the facts?

However I certainly would like an expert to chime in to verify just what those SMART numbers are based on. Shawn gives a certain number and states that over those numbers indicates a problem. How were those numbers determined? Could there be other factors that lead to high Retract and Realloc numbers?

Your nearly-new iPod certainly should not be in that situation unless the HD was a faulty one to begin with.

I don't have the same error, but mine wont sync either. Usually about 400 songs will go on, then there will be a corrupt file or something and I get a windows error saying "Windows Write Delay", or an error on iTunes (error - 48) I thought it might be a corrupt file, but it always gets that message at different stages of the sync and with different albums and songs.

Hmm. I think you might need to research the Windows section of the iPod, and look for the sync issue that more closely matches what you are seeing. Although the check you did for the SMART status and the numbers you listed which, according to Shawn's explanation, might mean a wonky HD could be a clue.

Apple lists several troubleshooting steps (may be different for Windows) that you might want to follow. I know that restoring the iPod should be a likely first step. The other might be to create a small playlist of files you are certain are not corrupt, manually sync the iPod to them after restoring and see if all goes well. If it does, then you might be dealing with problem files. You could continue adding files in chunks of 10 or so to eliminate the problem files.

The chunk idea isn't bad. Despite the number of retracts/reallocs, if the problem is with a corrupt file rather than the drive, that'll narrow it down pretty quickly. If you remove files that seem to cause problems, but then you start to see problems again once you exceed a certain amount of storage space, then the problem is almost certainly the drive.

As to what those numbers mean:

Retracts refers to the number of times the hard drive's read/write heads have "retracted", or moved away, from the drive platters, usually from an unplanned power-off. I'm not quite clear on what the consequences of this would be to the drive.

Reallocs refers to reallocated sectors. When a modern hard drive encounters a read/write error on a particular sector, the drive's controller will mark that sector as "reallocated" and move the data to a new area of the drive. A large or climbing realloc number is a pretty clear indication that something problematic is happening to the drive.

The third number, pending sectors, refers to sectors that the drive plans to reallocate because it has had some difficulty with them, but hasn't had a chance to actually reallocate for whatever reason. A high number here can also indicate potential problems.

The power on hours number, to the best of my knowledge, refers to the amount of time the hard drive has actively been spinning, not the amount of time the iPod has been used. As you've probably noticed, the hard drive will spin up for a very short period of time, load the data it needs into RAM, and then spin down. My own 80GB iPod classic, which is over two years old and has seen moderate use, has 56 power on hours.

The number of retracts/reallocs I gave as indication of a problem aren't any kind of scientific or official determination, but a personal threshold, based on my own experience, which is that generally, when people come to me with weird sync issues on a hard drive-based iPod, SMART will almost always indicate issues with the drive. It sounds kind of like circular reasoning, but the correlation is there.

What causes these hard drive issues? I don't know - I'm not an engineer. When you consider the tolerances of the parts inside a hard drive versus the external forces that come into play when moving around with an iPod, I'm sometimes amazed the drives survive a day, much less years.

One last note, which is if you just purchased your iPod new this past June, jbkenney, it should still be under warranty.

Shawn

My 80GB has been acting strangely. It started with the song time counter freezing while sonog was still playing,if I clicked to go to the next song it would not go. Then after a few seconds or so it would jump to the next song. Today I reset the iPod and the Music menu shows NO MUSIC but the Settings only shows 16GB. I did the diagnostic as you said and I have 7 retracts and 0 reallocs. This would appear that the HD is not failing I hope? However, the Music menu still shows NO MUSIC after Reset. What else can I do? Should I do a Restore? I do have all my music backed up.

I agree with you in that I don't think that your hard drive is the issue here. I'd try restoring the iPod, but you said that iTunes doesn't recognize the iPod properly. I think your next step should be to [force the iPod into disk mode|http://support.apple.com/kb/HT1363] and attempt to plug it in and restore it from there.

Shawn

I'll try putting them all on in chunks next