EEVblog #135 - Kindle Case Mythbusting

Dave investigates the Amazon Kindle 3 reset/lockup problem that countless people have been having with the leather case.
Is it the metal tabs shorting something out, or something else?

I don't have a real non-light case, if someone does and wants to donate it for experiments please get in contact!

[EEVblog]

@andycr2048 For the millionth time, I was just testing the myth that it was the metal contacts shorting something, that rumor was making the rounds when I shot this video. Never have I doubted that the non-lighting case is causing problems.

[EEVblog]

@crazypete05 You clearly missed the entire point of the video, which was explained (clearly I thought) up front.
There was a rumor that the metal contacts were shorting out the contacts in the connector. That CAN be investigated and tested without the actual case. In fact to prove it I would have had to rub the coating off the contacts on the real case to make it EXACTLY like the case I used.

[kedwa]

Great myth-busting! :-)
The symptoms described sound ominously like capacitor plague symptoms. I wonder if the problem is faulty capacitors? You would need to get hold of one of these malfunctioning Kindles to find out the problem.

[EEVblog]

@thespeg Highly unlikely, as the reports are saying that the problem goes away instantly when not in the case. And the consistency of the reports indicated a more specific problem than random paint flecks.

[BadQuantum]

One of my preferred moments ... Watching the testing and hearing the logic for such. Great work Dave.

[EEVblog]

@SkaOfCA No, the LED simply connects across the two (open) terminals

[EEVblog]

@frank26080115 I do operate it, but didn't get that on camera, sorry. I've added an annotation note. I operated it for some time, including power ON-OFF and WiFi/GSM operation.

[Gameboygenius]

My two theories:
1) The other case doesn't short at 0 ohms, but maybe 5-10 ohms and hits a "sweet spot" where the protection doesn't kick in, but the you still get current overload.
2) Latchup: First, the bottom input is safely grounded, and also connected to the LED driver. The LED driver can sense the short, no problems there. Then suddenly, the bottom handle loses contact with ground, but not TX/the bottom pin, and causes latchup since it's 1.8 V logic, while the LED driver is 3.x V.

[Mycroft]

Hi Dave, I watched your kindle case mythbusting vedio.
My kindle suffered the same problem. What I did is took it apart, first, took out the brass spring in the upper hook. Problem was still there. And then, I used tape to completely disconnected the four contacts with the mother board. This time, problem solved. I'm not a EE but my theory is some Kindles have defects with that four contacts and the non-lighted cover triggers the reboot problem. Not every people with the nonlighted cover -->

[candyrain]

I know this is an ancient video by tech and youtube standards, but I wanted to thank you for an interesting look at how these things work. I have zero electrical knowledge and some of what you said was gibberish to me, but it gives me hope that my idea can work: either harvesting an LED strip and diffuser panel from a Kindle Paperwhite (with a dimmer switch/toggle?), or coming up with a DIY alternative, to install onto a Kindle Keyboard. I love the Paperwhite's lighting but can't stand the size and lack of buttons, and can't afford the Oasis, which frankly doesn't look satisfying to use.

[EwanMarshall]

Do these cases have magnets in to trigger read switch for auto-sleep/wake I know the newer kindles and cases do, as do quite a few similar devices. (My tablet does to)? I'm thinking just unlikely chance the the movement of the magnet when opening it is causing just the wrong stray current on just a particular track (the nexus 10 pogo pins seem to have this problem).

[slade]

I am still using my Kindle 3 with the non-LED official case. I have one vague memory of accidentally picking the Kindle up by the Kindle itself - not the case it was attached to. The painted hooks on the case would be pressing against something inside the Kindle. It died. Turned itself off. I had no problem turning it back on. Other than that, I haven't experienced any issues with the case or my Kindle resetting or dying.

I have had my Kindle freeze occasionally. I could not get it out of standby mode. I let the battery die. After recharging the battery, all is back to normal. Unfortunately, my battery normally lasts like 2 weeks so it takes awhile. Turning it completely off (screen goes white) when you're not using it seems to prevent that problem. Always leaving the Kindle in standby mode (random image on screen) increases the risk of a lock up. Occasionally resetting any device that I tend to leave on 24/7 seems to help me avoid problems. Whenever I remember to, I cycle the power on my mobile phone, Roku, Kindle, and Nintendo 3DS.

[sneakerset]

Hey, Dave. I've followed your train of logic (on the troubleshoot). You've suggested an ESD issue here, correct? I don't have a Kindle available..but I'm curious as to the actual mounting points on the PCB (to the shell). Is there any indication of stress-related flexure (around the physical mounting points), or have you ruled that out?

[Satchmoeddie]

ESD or maybe a mechanical stress in the right spot on the PCB. My guess is ESD from a plastic case that should have had some carbon added to the mix to keep it from building up a charge. Usually pins for any connection are tucked in far enough to keep any shorting issues at bay. Thankfully I am too poor to run out and buy the latest gadget. I also like to see the initial failure rate of an item before I invest in it. Leave it to some twit to make a fatal carrying case for the darn thing!

[thomasquan]

I forgot to mention in my last post that I did replace the battery with a new one, and charged it for a day until the green light came on.    Still, that didn't fix it.

Thanks for the video - great job!

[rpare]

I have had the Kindle 3 reboot whilst placing in a ziplock bag.

[EEVblog]

@shiftplusone80 Done that, screwed it in place and left it while operating. Nothing.

[EEVblog]

@Gameboygenius Other have measured the real case properly as being completely open between the two contacts.

[Dibblah]

It is an input - At the console, you can see the "Accessory detected" message. Interestingly, it doesn't appear to be dumb - it's some sort of one-wire thing.

[TheChrist]

Hi Dave. God Bless you mate. I really am having trouble with my Kindle 3rd Gen WiFi only. I have tried all rebooting methods, recharging for 30 Mins. rebooting again, etc... The unit is frozen on the book list menu all the time. The yellow led turns on when plugged-in to the adapter, but, the green light does not. Why is it frozen like that? Can you help me in understanding this idiotic problem Dave? Do you suggest I just ask Amazon to give me a new one? Amazed at yor knowledge too. Thanx