# A theory on the cause of the case reboot problems...



## Morf (Nov 18, 2010)

I've been quite vocal on here pointing out that not all the unlighted cases cause reboot problems. I even stated that I knew of three people with unlighted cases (besides myself) and none of us have had problems.

Well, it turned out the other day I was wrong, and one of my colleagues had been having reboots! 

I got a chance to compare his case with mine. I wanted to get pictures, but I was at work and couldn't do, but there were some slight but noticeable differences between the cases.

The "leather" strip which holds the clips on his (red) case seemed much thinner than on my (black) case, and almost made me feel that it was plastic "pretend leather" whereas mine feels like real leather.

More importantly, the coating on the clips seemed different - it's a few days ago now, and I can't remember what the difference was, but one was smoother and one was rougher.

Most importantly, the coating on his was worn at the end of the bottom clip... there was brass visible there. Mine are still completely perfect.

Now, we know there are very strange things going on inside the clip slots - there's even a serial port in there - see http://www.youtube.com/watch?v=lypYZxIDBDs and although nobody yet knows for sure what's causing the reboot, my theory is that it's related to the paint on the clips being *slightly * worn.

My experience shows that the Kindle is OK if the clip is fully coated doesn't short anything out in the slot.
Dave's video shows that it's also OK if the clip completely shorts out all four connectors in there.

People with the problem have reported it going away if they cover the clips, but also if they remove the paint completely. http://www.kboards.com/index.php?topic=48749.0

Therefore I think the problem is happening if the clip partly but not completely shorts out - maybe only shorting a couple of the connectors. This means that the shorting occurs, but the overload circuit that Amazon have fitted in there doesn't react (or maybe doesn't react quick enough) and the reboot occurs.

Thoughts, anybody?


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## River (Jan 15, 2011)

I also suspect in that way after seeing the Dave's clip on youtube. 
short circuit may has no problem at all, but resistive contact might cause the problem. 
One thing I don't understand is that it's so hard to reproduce the freeze/reboot situations.

I just sanded off the lower hinge then reboot problem went way. 
I'm wondering about the purpose of the paint.
it might not be something to insulate hinges from the biginning.

here's my work

http://dawnriver.tistory.com/460

PS)
And...... My leather strip around hinges looks like a artificial one(like a thick vinyl)


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## Morf (Nov 18, 2010)

River,

Apologies, I should have credited you in my first post because it was you who linked to Dave's video and got me to thinking about this!

Anyway, your case looks very much like my friend's case, with the thinner leather strip. For comparison, here's mine in a similar shot:










You can see that the strip looks a lot thicker, the stitching hasn't pulled it down like yours has. It's also quite uneven.

Here are the clips on mine:


















Notice the coating, which is thick and completely undamaged.

Finally, a new thought, there is a code on my case which I think is a date code:









(camera struggled with that one! )

I read that as a date code: 2010 week 31. My colleague's (which looks much like yours) had a much later code on it (haven't got the number here but ISTR it was about 10 47).

I bought my case in September, he got his at Christmas, which does support the date code quite well.

Now this is all hypothesis, but there are significant differences between my case and yours/his, and I have no problems, you have problems.

Manufacturing change, Amazon? Are we looking at a production problem like the keyboards where the printing wore off?

PS) River, can you post the pictures from your blog here so people can see the difference?


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## River (Jan 15, 2011)

That's fine, I also found the clip on line somewhere else 

Mine also has the numbers of 10 48 01 (2010 48th week?). It's around your colleague's date code.
Your idea sounds great. Something might changed.

I sanded off the paint of lower hinge a week ago and I have no reboot issue now.


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## Morf (Nov 18, 2010)

The difference in the strips is quite apparent, isn't it?

My strip is thick, black round the edges, flat across the stitching and quite uneven from end to end (not so clear on the pictures, but it rises and falls noticeably along its length).

Yours is thinner, light around the edges, pulled down at the stitching and smooth from end to end.

I'm not blaming the strip for the problem - that's only decorative! - but to me it is clearly indicative of a change in manufacturing or factory. I think the thinner paint is the problem (look how thick mine is), but the strip is an easy indicator of the difference.

Anybody else with a good or bad case who can comment?


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## Gail K (Feb 26, 2010)

I took my Kindle out of the case, and I hate to debunk your theory, but the hinges are completely covered, not scratched at all.  The strip looks the same too.  I had to get a magnifying glass to see the numbers, but it looks like 10 31 and the third number is a two or three.  So everything looks the same as yours, but I'm having problems and you're not.

I misinterpreted your message in the thread I started.  You said I wasn't seeing the reboots.  Of course, I'm seeing some reboots, but you probably meant that they were also happening when I wasn't looking.


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## Morf (Nov 18, 2010)

Gail,

Thanks for that, it sounds like your case is the same batch as mine, but whereas mine is fine, yours is giving problems.

Ah well, that's another theory shot down! I really hope Amazon have some idea what's going on, because it's got me beat!  

You're right about your thread, when I said you weren't seeing the reboots, I meant that literally, that they were happening but you weren't seeing them happen because you were elsewhere at the time.


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## intinst (Dec 23, 2008)

Could be more than one manufacturer, with one using the thick paint and the other something else. Would also explain the differences in the leather, one was skived thinner than the other.


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## Morf (Nov 18, 2010)

Yes, I suspected either a different manufacturer or a change in Amazon's specification to the manufacturer (cost cutting, perhaps?).

Unfortunately, Gail is having problems with a case which sounds to be identical to mine, which means the differences are "something of interest" rather than a likely cause of the rebooting problems.


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## ff2 (Oct 20, 2010)

Is the internal contact made with the hinges' top or bottom surfaces?  It would be hard to see the bottom surface without a dental type mirror.


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## Morf (Nov 18, 2010)

Interesting thought. It's not clear, so I may be wrong, but looking at the video at about 07:15 where he fits the contact block onto the case clip, I think the contacts are below the clip so they are contacting on the bottom of it.


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## River (Jan 15, 2011)

ff2 said:


> Is the internal contact made with the hinges' top or bottom surfaces? It would be hard to see the bottom surface without a dental type mirror.


I also think like Morf, it should be the back side(bottom surface).

My upper hinge's top side looked intact but when it got inside kindle, 
it was connected with something inside. (maybe the + terminal of kindle battery)
Impedence(resistiveness) between two hinges went from open(infinite) to around 200K Ohm.


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## River (Jan 15, 2011)

FYI 

Untill now, my kindle rebooted once in 15 days(15th Jan ~ 30th Jan) 
after sanding off the paint of lower hinge. 
Surely there's something more in reboot issue, but I'm happier because it reboots much less. 

I think it's worth sanding off the paint for someone far from Amazon CS like me.
(just for first aid. just for the unlighted cover problem)

But I''m a bit disappointed Amazon doesn't ship many(almost all) covers to S. Korea.


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## palaran (Dec 29, 2010)

Mine had no problems initially, but in the last couple of weeks has started to develop what seems to be the case problem. Called Amazon customer support tonight and within a few minutes after just one or two questions to confirm what the problem was they had arranged for a credit to be added to my account to allow me to buy the lighted case, no quibbles. 

Can't fault them for customer service.


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## Tabatha (Oct 4, 2009)

Morf said:


> Yes, I suspected either a different manufacturer or a change in Amazon's specification to the manufacturer (cost cutting, perhaps?).
> 
> I have a green unlighted case, and date on hinge is 10 29 03, and where your leather strip looks pebbled, mine is very smooth like the edge of case, and hinges have smooth thin layer of paint. Just noticed bottom hinge has a mini spot on very edge where gold is showing thru, so paint must have worn off, or the edge somehow got niched on trying to insert it into kindle? It was purchased from the Warehouse deals as it was a bit cheaper than the new ones. It had started rebooting often, about a month after purchasing the cover. I have since replaced it with a lighted cover, which I am not having any problems with. So I do agree, with Morf that there were different manufacturer's, each using different paint and leather strips.


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## Morf (Nov 18, 2010)

Resurrecting an old thread, just to add a bit of new information...

As most people probably know, Amazon eventually pulled the unlighted case from the store, and after a month or two it re-appeared with, according to Amazon:

*Updated patent-pending hinge...*

I got my first look at one of the new unlighted cases this weekend, and this is what they look like now:










Yes, the hooks are now uncoated brass, just like the lighted case!


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## Elk (Oct 4, 2010)

Intriguing. 

Thanks for posting.


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