iPod 5.5Gen permanantly on AC power???

[podpodpod]

The subject says it all

My ipod shows that is plugged into ac even though it is not
I have rebooted, taken the hard drive out, tried pluggin into pc, installing lates build..etc

This is a nuisance because i cannot shut it down without it restarting again!!!!

currently waiting for the battery to drain


thanks for any help

[zajacattack]

http://www.fixya.com/support/t234007-ipod_shows_its_charging_when_not_plugged

These people have similar problems (as I found by a Google search). Only a temporal solution is listed though. Let me see if I can find a permanent one.

And, if that fails, read http://discussions.apple.com/thread.jspa?threadID=1325689&tstart=240

[dreamlayers]

I dealt with a similar problem.  A friend's video iPod, IIRC 5G, wouldn't charge through USB and would always detect that USB power is connected.  I posted about it here.

It would shut off from Apple firmware (probably because off there is sleep) and it would charge from Firewire.  He was using it that way for a while but now he says it won't turn on.

Edit: I now have this iPod.  I reattached a broken-off inductor and now it runs as before, always detecting AC power and using USB power.   I am planning to do additional troubleshooting to try to solve the USB issue.

[podpodpod]

I ve checked all of your links..thehy dont seem to help

I have never charged my ipod from the AC power...always USB charging

I still have not been able to turn the ipod off....and it shows a AC charging symbol on the battery all the time.

Obviously this is not a rockbox error..
Something to do with hard ware..? battery possibly?

thanks

[podpodpod]

basically

now my ipod is completely screwed over...

anyone got any ideas as to how i can backup all the data from the ipod hard drive...
i cannot use the ipod to do this..

[zajacattack]

You could remove the harddrive and then use an adapter to hook it up to a PC in order to save the data.

[dreamlayers]

I measured the voltage at the USB +5 V input and it was 3.7V.  Even if loaded with 1 kiloohm it was around 2.2V.  The voltage is there even when the iPod is asleep.  Power is not supposed to flow backwards like that on USB.  Another iPod without these symptoms shows virtually zero volts there.

I suspect a failure in the LTC4066  USB Power Manager with Low-Loss Ideal Diode and Li-Ion Battery Charger chip.  It's located on the button side of the circuit board.  I suspect that the failure may be due to use of a bad USB charger or perhaps a surge.  

With this failure the iPod may claim that it's charging via USB but not actually charge.  You can verify charging by viewing the battery graph in the debug section of Rockbox.  If you take an iPod that is deeply discharged and unable to charge through USB and you plug it into USB, it will appear totally dead.  Try charging through FireWire instead.  You may still be able to use USB to transfer data, just remember that it's not charging or powering the iPod.

[zajacattack]

You might want to try replacing that chip (if you can) to make sure that it is causing the problem and nothing else.

[dreamlayers]

The LTC4066 chip is in a QFN package with a large pad on the bottom which must be soldered (for heat sinking I guess).  It is surrounded by tiny discrete components.  I suppose I could remove it by heating the whole chip.  I'm not sure I could successfully solder a chip there.  It seems like it'd be too easy to create a short, move one of the tiny surrounding components or overheat some components.  Any suggestions for how to do it?

[zajacattack]

My expertise ends here. If you don't think you can do it successfully, though, my advice is, don't do it. It's not worth destroying your whole player.

[dreamlayers]

I'm practically certain that the LTC4066 is at fault.  I cut the USB power input (IN) which leads to pin 9.  That is by far the thickest of the traces which pass under the clickwheel ribbon.  After this, there was voltage on the LTC4066 side but not on the USB side.  There is no reason why the LTC4066 should ever output power through IN if it's not defective.

The cut of course disables USB charging, but that didn't work anyways due to the LTC4066 and Firewire charging still works.  Detection of +5V from USB is done on the USB side of the cut, and so the cut allows it to work because it stops the LTC4066 from feeding the USB +5V detection circuit.  This allows the iPod to be shut down from Rockbox.

I wanted to connect a diode from USB +5V to OUT of the LTC4066.  That would restore ability to charge from USB, though the lack of current limiting might be a problem in certain cases.  I didn't try this because of the extremely small amount of space available and concerns about the diode overheating.

This concludes my attempts to repair this iPod unless I run across some method which makes me think I could replace the LTC4066 without ruining the board.