Is my Kindle really dead

[patthecat]

Hi,

I've been trying to rescue my Kindle 3 for a few days now and fear it is dead but would appreciate some thoughts.

My Kindle has been working fine until I picked it up one night and the screen was completely blank. I assumed the battery was flat so charged it over night but the screen remained blank and would not power on as normal.

I have tried holding the slider for 50 seconds to hard reset it many times. I have tried to recharge it. The yellow light comes on for about 10 seconds and then goes out. I have tried a pc/usb charger and a kindle wall charger.

I then removed the battery, pressed the power slider to discharge any residual and reinstalled the battery. The green light comes on for about 10 seconds and tthen goes out again. I tried a hard reset again with no joy.

I tested the battery and it appears to be holding the expected charge.

I have tried to use Kubrick but the Kindle doesn't appear to enter USB download mode and hence Kubrick doesn't detect it. In fact when the kindle is connected to Windows it is never decognised in anyway as a new attached device.

I think it may be dead but would appreciate any thoughts.

Many thanks

[knc1]

Originally Posted by patthecat

I tested the battery and it appears to be holding the expected charge.

Technical details of how you tested the battery and what the results where please (like in, post numbers and method).

[patthecat]

I used a multimeter which showed 4volts out compared to the battery rated output of 3.7 volts. I assumed the slight over voltage would be normal for a fully charged battery?

[knc1]

Originally Posted by patthecat

I used a multimeter which showed 4volts out compared to the battery rated output of 3.7 volts. I assumed the slight over voltage would be normal for a fully charged battery?

Correct.
Full charge on that battery would show 4.2v open terminal.
So it is probably better than 90% of full charge.

Now the next problem -
The open terminal voltage of a Li-Ion battery is not an indication of storage capacity.

You could be reading this open terminal voltage across a battery with all the storage capacity of a hearing aid battery (the smallest thing I could think of while typing this).

Translation: Your battery may not be able to support the current draw required, long enough, for the device to complete booting.

Which is what your original description sounds like.

Translation: Your Kindle is not really dead, but that battery is ready for the re-cycle bin. Replace it.

Hint (not a recommendation for the non-technician):
You have the K3 open, you have the battery out - - -
The K3 firmware does not check for an "Amazon Brand" battery (other firmwares do check) - - -
Try hooking up a fully charged external stack of three NMH (Nickel-Metal-Halide) or Ni-Cad batteries temporarily and see if the Kindle will boot.

BIG NOTE: The 3G modem pulls 4 Amps when it transmits a burst, so turn 3G off!
That external stack above can't provide that sort of load current.

BIGGER NOTE:
There is a battery condition test in the "Diags" menu - -
BUT Some K3 diags firmware requires a serial port connection to exit from the diags mode!
Translation: Don't "ENABLE_DIAGS" on a K3 without a serial port connection available!

[patthecat]

Thanks knc1,

I will give that a try tonight when I get home and will let you know the outcome of connecting an external battery stack. Wifi was off but as I have hard reset it I assume the default state is on so will turn it off if it does in fact boot.

I don't have a serial port connection so will avoid the diag for now. Thanks for the notes.

Thanks

[knc1]

Originally Posted by patthecat

Wifi was off but as I have hard reset it I assume the default state is on so will turn it off if it does in fact boot.

Sorry, I made a think'o in that post, have corrected it now.
Not the Wi-Fi modem, the 3G modem is the one that pulls a very high current during transmit.

But your point may be correct - no telling what state the system is in after "partial boots".

All we want to do is find out if a good battery "will fix it" - before spending the bucks on a new battery.
Don't expect the Kindle's battery management chip to be able to keep those external batteries re-charged - it is "programmed" for Li-Ion.

[knc1]

Just a few links for the hardware shopper -

Batteries (for the external battery stack):
http://www.bgmicro.com/BAT1094.aspx
or
http://www.bgmicro.com/ur18650f-2000...-by-sanyo.aspx
(not sure if those are 'AA' size but they look like it in picture and I don't know if those are 1.2v single cell, or a cell stack)

Battery holder (for the external battery stack):
http://www.bgmicro.com/battery-holde...lder-tabs.aspx
or
http://www.bgmicro.com/battery-holde...terminals.aspx

Those Li-Ion batteries **do have** enough storage capacity to run the Kindle (and so do the Ni-MH batteries, but may not be able to supply the peak current required by the 3G modem).

Total cost: about $8

Battery charger for 1 or 2 of the Li-Ion batteries:
http://www.bgmicro.com/18650-battery...-with-led.aspx
Another $8
(The charge specs. suggest that the 18650 is a 3.6v, 3-cell, device).

Ah, well, those folks have e-mail address and telephone number to clarify the above unknowns.

(Personally, I have to lockup my credit cards before going to that site.)

[patthecat]

Thanks for the links.

I got hold of a working K3 and swapped the battery into my kindle with the same result. It showed no signs of life again except as described above.

I also placed my battery into the other kindle and my battery powered up that kindle just fine.

I'm not sure what the next step is? Hopefully it isn't junk.

Thanks for the replies.

[knc1]

Originally Posted by patthecat

Thanks for the links.

I got hold of a working K3 and swapped the battery into my kindle with the same result. It showed no signs of life again except as described above.

I also placed my battery into the other kindle and my battery powered up that kindle just fine.

I'm not sure what the next step is? Hopefully it isn't junk.

Thanks for the replies.

That should rule out battery problems.

Strange.
Nothing comes immediately to mind.

Hopefully it isn't junk (because that might mean mine will become junk).
Let me think about this some more.

PS: If you still have access to the working K3, and that working K3 has the KUAL launcher and KUAL battery report button installed - -
You could run that report on both batteries, just for the information. (Report includes "storage capacity" of the battery)

Thinking . . . .