Aura HD Blank screen after depleted charge

[EndlessWaves]

Last night my Aura HD informed me it had run out of battery (despite showing 30% only a day or two ago) but now I come to recharge it there's no sign of life. I've plugged it into it's USB cable (the same port I used to transfer books) and despite having been plugged in for several hours the power switch doesn't do anything. The light that usually comes on isn't coming on and the screen is completely white.

This is the first time I've flattened the battery so I'm not sure what's normal but it does seem like something is wrong.

With the sudden battery drop I did turn it on and off a few times to make sure it wasn't a glitch. Among a couple of low battery warnings I did see a black screen with a progress bar that said something like restoring but I don't remember the exact actions I did with it after that.

After seeing no life after a couple of hours on charge I did try the reset switch. This caused the screen to flash (black white black white) and the power light to come on (steady for a few seconds) but no activity otherwise.

Before I contact kobo support is this a known problem or can anyone suggest a possible solution? It's one of those ones that's difficult to search for and I haven't found anything relevant.

[icallaci]

I haven't seen this behavior. I have two Aura HDs, and their batteries went below 10% when I was having the battery-draining problem, but when I charged them up, everything came to life normally. Good luck.

[rem736]

you did not mention whether or not your kobo was still connected to power when you attempted to reset/power it up. if not, with the usb cable still connected to the kobo and the charger, try to do the reset/power up. i never ran out of power completely on my kobo but there was an instance where it would not power up on me and connecting it to power while powering it up did the trick.

[TechniSol]

If from reading your original post, it was restoring and you shut it off, or the battery was too low to finish, in the middle of that process you may have screwed the restore up. Maybe charge it fully and try the full reset with paperclip, light button, etc, held in while switching power on and see what happens. Try it plugged in, etc. Good luck.

I would strongly caution you to never interrupt a restore on the off chance things get garbled up. That's about the last time you want to power things down, while it's trying to fix your firmware...

[Athropos]

The battery of my Aura HD depleted twice and I had no issue recharging it. AFAICT, I just plugged it in and it worked.

As for the battery indicator, it's inaccurate in the sense that the battery is depleting very slowly above 90% and very fast below 30%. I know that I have maybe 1 or 2 hours left where it reaches the 30% mark. I've read here and there that a few full charge/discharge cycles are needed to get an accurate indicator, but in my case it's still as inaccurate as it was in the beginning. Looks like Kobo is not aware that the voltage drop of the battery is not linear.

[TechniSol]

The behavior of your battery meter sounds just like mine on the Touch and the Glo. Slow to start showing drain at the top end and much faster the last 25⅝ shown. Probably because they never calibrated a curve to allow for the voltage dropping off much more quickly vs. remaining current on the low end of the curve. It's enough of a change that a table of values might have been better than trying to fit a curve, though I do wonder that the curve may move around a bit as the battery ages.

[EndlessWaves]

Originally Posted by TechniSol

If from reading your original post, it was restoring and you shut it off, or the battery was too low to finish, in the middle of that process you may have screwed the restore up.

After talking to kobo support it turns out that simply touching the light and power buttons together will activate the full reset on the Aura HD. While I can't blame them for not blocking it on a low battery/unconnected (these things can get incorrectly detected) it does seem to be a design flaw that it's so easy to activate that I did it accidentally.

After much mucking about trying different combinations of resets and connectedness I did manage to get it to charge and activate the full reset which seems to have brought it back to normal with no lasting damage.

[TechniSol]

Congratulations! I was really worried that having it shut down in the middle of a restore cold be bad news, but maybe it's more robust than I thought. If anyone can speak to just how robust the restore mechanism is I'd love to hear it.

[didoto]

Hi EndlessWaves,

Wow.
I got the same situation! Just that I think I performed several factory resets purposely - I thought it would solve problem, but I did not even imagined such problems with not charging.
I should have read the forum first thoroughly
I hope I dod not screwed it completely...

Could you give me some more detials what have you done to make it going?
"After much mucking about trying different combinations of resets and connectedness I did manage to get it to charge and activate the full reset which seems to have brought it back to normal with no lasting damage."

Thanks for your shared experience!

Originally Posted by EndlessWaves

After talking to kobo support it turns out that simply touching the light and power buttons together will activate the full reset on the Aura HD. While I can't blame them for not blocking it on a low battery/unconnected (these things can get incorrectly detected) it does seem to be a design flaw that it's so easy to activate that I did it accidentally.

After much mucking about trying different combinations of resets and connectedness I did manage to get it to charge and activate the full reset which seems to have brought it back to normal with no lasting damage.