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How a Leather Cover Crashes the Kindle
An anonymous reader writes "Amazon has started offering refunds to Kindle owners who own the unlit leather case who claim that it causes their Kindles to reboot, but are playing dumb on the cause: "our engineering team is looking into this." People have been wondering how a leather cover could possibly crash an electronic device, and why is Amazon offering money back if they don't think there's a problem? It seems that some of the folks over at Connectify have figured it out, and it's a doozy!"
Lest we forget:
http://ftp.sunet.se/jargon/html/magic-story.html
Palm trees and 8
It looks like a flaw on the part of the cover maker. Amazon could put some amperage limiting circuitry, but I imagine it would raise the cost.
Someone had to do it.
Maybe they can substitute the metal now connecting the hooks with extremely fine steel wool. Then everyone will remember it's the Kindle.
We constantly hear about needing to "program defensively" and test for "can't happen" conditions.
Here's one for defensive engineering.
not owning a Kindle I don't understand why there is even a need to have the two "hooks" connected in any way by a piece of conductive material.
They are not powering a lamp, they just keep the Kindle attached to the leather case.
I like microcars
a malfunction in a high tech device that actually can be fixed with duct tape
First, his meter's reading 2 Megaohms, not 2 Ohms. I guess he's not much of an "Electronics Person". Second, it would appear that he's measuring conductivity though his body to achieve that number. Both of his fingers are touching the probe tips.
I'm assuming it was done simply for price - the case with the light uses the hooks for power, so rather than having two entirely separate designs they just left out the light and painted over the conductive parts (and apparently didn't do a very good job of it...). Probably cheaper to mould 10,000 pairs of hooks out of metal and then paint over half than to make 5,000 out of metal and 5,000 out of plastic.
It's a problem with the case design, not the Kindle, as far as I can see.
The linked article at Connectify says they measured a resistance of 2 Ohm, but on the picture I read 2 MOhm!
Check yourself with the large version of the picture.
Well, as long as it's rebooting that gives you at least a few moments while Amazon cannot delete your files...
The flaw is certainly in the cover(using two physically separated hooks, rather than a single piece of metal, would not have been rocket surgery and would have provided dielectric strength high enough to resist pretty much any voltage that wouldn't also kill the user.) However, we really have no way of knowing whether the cover maker failed to follow amazon's orders, whether amazon failed to issue the correct orders, or who was responsible for considering the situation where the + hook and the - hook are not separated by an LED and current limiting resistor.
If amazon didn't think about it, or naively thought that a thin layer of cheap paint would do, they fucked up. If the cover maker looked at a design document that said "Connecting hooks must be electrically separate" and said "eh, one painted part is cheaper than two physically disconnected parts, paint'll do." then they fucked up.
1 volt is enough if you can source enough current....
remember folks, VOLTAGE != POWER
First, his meter's reading 2 Megaohms, not 2 Ohms. I guess he's not much of an "Electronics Person".
Second, it would appear that he's measuring conductivity though his body to achieve that number. Both of his fingers are touching the probe tips.
That was the first thing I thought of when seeing the picture as well... Thank goodness he posted the full res version of that so we can very clearly see the M on the meter. What a maroon.
If you RTFA, you'll see the hooks are totally different. You're in the right vein, though. The unlit case looks like it uses a single strip of cut metal for the attachment hooks, a pretty simple design, and much cheaper than making hooks that aren't shorts.
My guess is the only reason they're painted black is because they were aware of this problem and thought that would fix it good and cheap. Or the paint is simple corrosion prevention and they didn't know...
When you're afraid to download music illegally in your own home, then the terrorists have won!
If it connects directly to the battery at about 4V, it will only draw 2A, or 8W. This should be enough to warm the case, but not to make it or the device burst into flames.
But that case was designed for the Kindle 2, which (I think?) *doesn't* put power across those pins. If that's the case, this is mostly a Kindle 3 design flaw - they should have made the slot spacing different so you couldn't use a Kindle 2 case.
It looks like a flaw on the part of the cover maker. Amazon could put some amperage limiting circuitry, but I imagine it would raise the cost.
Look closely at the dudes meter, its 2 megohms not 2 ohms. Lets guess its a single cell li-poly at 3.7 volts. Thats a smokin' current of 74 microamps. What, a quarter of a milliwatt, something like that?
Good luck building a 74 microamp fuse. I once built a microwave preamp in the 80s and static fried the active device, that probably was a 74 microamp fuse, in a weird sort of way.... Active current limiting at that level is kind of a mystery to me... I suppose you'd need a mosfet off resistance in the hundreds of megohms since the load impedance is in the single megohm range, but PC board leakage currents are going to be a problem at that level. Leakage currents thru the plastic kindle case would probably be in the microamp range?
"Science flies us to the moon. Religion flies us into buildings." - Victor Stenger
You suppose wrong.
We used AA batteries in prison to light cigarettes when they took away access to the wall sockets.
Still waiting on Serviscope_minor to wake up to fucking reality and realize that Jessica Price isn't going to fuck him.
Being a product manager, I would guess that whomever wrote the spec for the cover latch, specified dimensions, and what is required for it to be a sturdy fit. But that they forgot to specify that there was to be no electrical connection or conductivity between the tabs.
The Winning bidder probably chose to make the bracket out of brass (guess here) to ensure dimensional integrity, and because a plastic mold for a thermoplastic injected part would be a couple tens of thousands of dollars.
But, I would bet my last dollar that someone at QA at Amazon figured this out, and specified that the bracket had to be painted with a non-conductive paint as a band aid.
This is how trivial, serial bad decisions come back to bite you in the arse
Suppose you were an idiot and suppose you were a member of Congress
I got a Marware cover for my iPad and love it. One issue it had though, was that the iPad's compass simply never worked. It always gave me the Figure-8 Shake warning, and I eventually thought that perhaps my iPad was defective... Then one day I noticed that the flip out "foot" in the cover is held in place by two magnets. Whoops. Really only an issue if you use a compass app or if you want to figure out directions while not moving, but an interesting design issue none-the-less.
That's actually a terrible idea. Limiting the current through the hooks would still result in lots power being wasted, just not enough to crash the device. Over time this will cause the battery to discharge completely, which results in the owner charging it, which leads to greatly reduced battery lifetime.
If you run your batteries between 20% and 80% charge, you get orders of magnitude more life out of them compared to running them between 10% and 95% charge.
-1 disagree is not a modifier for a reason. -1 troll, flaimbait, redundant, overrated are NOT acceptable substitutes.
I've got a Kindle and case from before the new version, with the possible lighted case, existed. Obviously I can't know whether or not the lighted version had been conceived when my case was designed.
But the hooks on my Kindle cover ARE metal, and ARE painted black. I assumed (& still believe) they were metal instead of plastic due to the increased strength of the metal hooks, and that they were coated/painted for esthetic reasons - the hooks feel more comfortable if you touch them, there is less chance they'll scratch the Kindle as you attach it to the cover, and they look more elegant, all perfectly reasonable reasons.
I don't think this is a case of anybody taking a shortcut somewhere to lessen the cost of anything.
How exactly do you fry an ebook?
A demonstration for you:
1) Purchase Kindle
2) Purchase and download 1000 ebooks to Kindle
3) Throw kindle into incinerator
4) Purchase new Kindle and click "Sync"
5) 1000 ebooks "magically" appear on new kindle and more remarkable show no signs of fire damage.
Plastic has the virtue of being non-conductive, but my guess is that such a tiny part made in plastic could be problematic in terms of strength.
A work that expires before its copyright never enters the public domain and thus enjoys eternal copyright protection.
Fahrenheit 404?
-- I'm not a pessimist, I'm a realist. It's not my fault that life sucks so much. --
Breakdown: The lighted case gets its power from the connectors that hold the Kindle in the case. The unlit case has these two connectors physically connected even though there is no light. Putting the Kindle into the unlit case where the metal contacts are clean causes a short between the two connectors.
The ability to get power through those connector points was by design in the Kindle or the lighted case never would have been able to be designed the way it was.
It sounds to me like the engineer(s) involved with the unlit case did not communicate well with the Kindle engineers or vise versa.
Remember to maintain your supply of
"If you can source enough current..." as if you have any control over the current. It's a simple damn equation, people. V = I*R. For a given conductor, if you put one volt across it, a current V/R will flow through it. No, you can't magically wish for a higher current at the same voltage. Nor could you achieve an arbitrary voltage at a given current. If you can control both current and voltage, then BY DEFINITION you are changing the resistance.
Another one of my least favorites: "It's the current that kills, not the voltage." Actually, it's the stoppage of your heart that kills you, along with possibly the boiling and cooking of your internal organs. People take these sorts of sayings and end up making stupid decisions.
His fingers appear to be touching both metal probes of the meter so 2 meg-ohms seems about right for his internal resistance.
And in the end, the love you take is equal to the love you make
I used to work on an old IBM AS400 which provided about 150 terminals (5250) to a bank. At random times, all of the terminals would lose connection to the AS400 which was located in the datacenter which was located in the floor below where everyone sat. The connections would only drop during the daytime, we could hook up all sorts of diagnostic equipment at night and almost never saw a drop.
After about 2 weeks of troubleshooting we determined that every time the elevator passed the cable infrastructure which was run down the elevator shaft, it would cause the terminal sessions to drop...
Imagine everytime you left the building at 2am after not being able to find a problem; to have someone call you and say "just as you were leaving the terminals reset..."
So all you have to do is scrape the paint, and wire in a little LED and resistor, and you have a free lit case? Thanks Amazon !
I want to delete my account but Slashdot doesn't allow it.
It's not a small current, it's the "Magic" (TM) :-)
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It looks like his finger might be touching the negative (black) probe, but on the positive (red) probe his fingers are all above the plastic ridge.
Support Right To Repair Legislation.
Jeff Bezos: "You're reading it wrong."
:)
Everybody gets what the majority deserves.
The paint on the hooks wears off and shorts out the device!
There now was it so fucking hard to put that in the fucking summary?
This never happens to my paperback version.
1000 minus, of course, the number of those ebooks that Amazon has decided can no longer be downloaded since the time they were downloaded into the old Kindle. Now, depending on how your tastes in ebooks line up with Amazon's whims in maintaining their public interest, that difference might be zero, or 1000, or anywhere in between.
Put a few of them in series and you can get a pretty strong current. Touch a wire from either end on either side of the rolling paper and it should ignite if it's dry enough.
The contents of alkaline batteries are poisonous and potentially explosive though... If a prisoner is too dangerous to be given a lighter or a wall socket, why would they have access to batteries?
http://www.metacafe.com/watch/866007/how_to_light_a_cigarette_with_batteries/
I don't know if you've heard of this website, it's kind of up and coming, called Google. You just type in something you don't know, and in about 10 minutes, you'll know it.
IBM 4341 mainframe in our data-center that would just shut down regularly every Friday night, around the same time ... shutdown coincided with the approach of the USS Lexington ... Apparently the radar from the ship was strong enough to ... trigger a shutdown.
Another IBM radar story (Third hand: CE involved -> my brother -> me.)
Shortly after the "Foreign Attachments" suit required IBM to allow other companies' equipment to be directly connected, there were a number of multivendor projects, of which this was one.
Each component worked fine in the respective labs. But the first integration of the whole system took place at the final site. (Why rent some space, hook it all up, get it running, tear it down, move it, and hook it up again, when you can do it once at the final site?) So they hooked it up and nothing worked right.
Several weeks of hair-tearing and finger-pointing by exasperated CEs from several companies ensued. At one point my brother's buddy had time on his hands and decided to fix the really annoying flickering fluorescent tube. He turned off the lights - and the tube kept flickering. WTF?
He called the other CEs over and demonstrated this. Then they all took a quick look around the environment to see what might be causing it. It was a short look: The wooden building was right next to the antenna for the airport's search radar.
Lined the room with conductive material. Everything started working just fine. Handshakes all around, exit stage left.
Bantam Dominique roosters crow a four-note song. Once you've heard it as "Happy BIRTHday" you can't NOT hear it that way
As already mentioned above, the multimeter in the picture is reading 2.164 megaohms which is quite a high resistance and would make no difference at all to the operation of the Kindle.
It seems that the blog owner has realised their mistake and replaced their blog entry with the content of another, but not before it made it's way into Google Cache
For those interesting in seeing the high-resolution "Oopsie" image, it is here.
While the ex-inmate above hasn't replied so far, I'd take his story above your Google result video any day.
Some things are best left to Google ("What's the capital of Assyria" etc), but turning that into "anything should just be Googled" is pretty counter-productive.
The thing about humans is that while they're slow they tend to give context and other random details quite readily. In this case I could perhaps get information on how to get the necessary steel wire/wool in prison, how to smuggle batteries, how to make the equipment last as long as possible...
Your Googled video does show how it's done (or at least one way of doing it.) However, it's terse, it provides no background on where this information came from and it just assumes you magically have the necessary equipment but not a lighter. It's a pointless party trick story vs. a story of something that was actually useful in prison.
Some things are best left to Google ("What's the capital of Assyria" etc), but turning that into "anything should just be Googled" is pretty counter-productive.
I've never disagreed with a sentiment so much before online. The internet is an incredibly vast wealth of knowledge and I feel that any time you have any question, it should be used accordingly.
It's amazing how much information you have access to, it is not difficult to self teach yourself computer programming, car mechanics, advanced physics, art techniques, or almost anything else using just internet information sources, and supplies at home to get you started. Obviously if you want to do car repair you should have a car and the tools necessary for the job, but understanding what to do and whats needed can easily be found online, with step by step guides!
The simple question "How does one do something" is the BEST kind of question the internet handles. There is even a popular site dedicated to it, howto.com - and Youtube will have tons of videos on topics like that.
The problem is that handy did not ask for backgruond information on where it comes from, he did not ask how to acquire those materials in prison, he did not ask about smuggling or manufacturing equipment - he merely asked how to light a cigarette with batteries. The video addresses that.
If, perhaps, he's interested on how to Smuggle items into prison - he should google "How to smuggle items into prison" and he can see the news reports on how people have tried to smuggle things in before.
I'm on the Connectify blog and I don't see anything about leather cases or flaws. When I search the page for "leather" I only see the tag and nothing else.
Darryl L. Pierce "What do you care what people think, Mr. Feynman?"
But you should be able to view a cached copy here:
http://connectify.blogspot.com.nyud.net/2010/12/why-leather-cover-crashes-kindle-3.html
Not sure if the change was intentional or what.
It's not just your eyes, the article is no longer on the blog at the time I'm writing this. Don't know why. Hopefully they put it back up so we can read it, though.
"I don't care about the Constitution!" --Bill O'Reilly, November 17, 2009
I wouldn't know, since the earlier blog entry has been retroactively changed to advertize Connectify, censoring the original content. Whether doing this on an article about the aptly named Kindle for Remote Book Burning is purposeful irony or not I cannot say.
Forget magic. Any technology distinguishable from divine power is insufficiently advanced.
Yep, in Mississippi, basically I was charged for having a cell phone and not reporting a crime I was present for because I was too goddamned drunk and passed out in the back of their truck.
What's fucked up is if I had actually stolen something from the vehicle in question, my charge would be dropped down by 3 years.
Mississippi needs to be nuked from orbit, just to make sure such obvious problems never happen again. Wipe out Sheriff Riley in Hernando County, Wipe out Judge George B. Ready for his corruption. He knew my lawyer wasn't qualified to represent me, and he let her do so anyways. He needs to feel at LEAST *ONE* of the TWO deaths I had to experience due to his ass.
Still waiting on Serviscope_minor to wake up to fucking reality and realize that Jessica Price isn't going to fuck him.