Recently the battery of my iPod 4G died. I did manage to get into Diagnostic Mode and tested the power: What exactly does the value after BATT mean?
I also did a harddrive check. Every time I did this, the iPod reboots and the value after RETRACTS increases by 3. So. What exactly does RETRACT mean? I searched Wikipedia, but I'm not sure I understand their description...
Maybe somebody can explain to me whether an increasing value of RETRACTS is a bad sign.
iPod 4G is before my time, but I suspect the hard drive has failed. I believe the retracts are an indication of when the firmware unloads the read-write heads. This can be in response to a full power down, or an attempt to reset the device following persistent seek errors. The temperature looks a bit screwy!
I thinkt the temperature value does not represent the real value in °C or °F, but the value minus 255. 329-255=74 makes sense. Values below 255 could, therefore, represent minus degrees. Correct me if I'm wrong.
Am I correct that the unloading of the heads only occurs in emergency situations, such as dropping the ipod, or if the battery is empty?
It may well be that the data regarding temperature has been corrupted. It's too high for a sensible value in either Fahrenheit or Celsius, and too low for Kelvin. Even if it is stored using an arbitrary scale or offset it ought to be displayed in a logical manner.
A reset is required to get into and out of diagnostics mode, and perhaps the act of entering the HDD diagnostics causes yet another retract which might explain the count of 3. What happens when you try to load data onto it?
It was really hard to open the iPod. I managed somehow. The iPod works again. The hard drive was not damaged. Hurray. However, the battery was swollen and seemed to have damaged the click wheel slightly. The "Back" button now works barely and the "click" is gone, whereas the other buttons work fine. Needless to say that the Diganostic Mode test works. Is it possible to replace the click wheel with this model? Couldn't find useful information on that topic.
My 7th gen iPod touch is having a boot loader issue. I ran the manual test, and these are my results:
Pending Sectors 0
PowerOn hrs 526
Current Temp 33C
It only does the boot loop when connected to a USB port (either to my computer or a wall socket). If I plug it into my alarm clock that has an iPod dock, it works fine (other than telling me it needs to be restored through iTunes).
I orignally bought this iPod about 3 years ago.
Edit to add: If I get it into disk mode and then plug it into my computer, it goes back to a boot loop. During the boot loop, while connected to my computer, it will not let me enter either diagnostics mode or boot mode.
Yeah, my device didn' even reset. I held onto the menu + select keys for 12 seconds 3 different times and it just keeps rebooting. It seems to keep rebooting before registering what I am selecting on the click wheel. The automatic diagnostic test says everything is working fine on the click wheel/buttons/hold button/head phones front.
I can get it into disk mode when it's on the iPod Alarm Clock Dock, but the second I connect it via USB to my computer, it starts the reboot loop.