Amateur Engineer Figures Out Why His Kindle Randomly Restarts

daffy4u · 12-21-2010, 08:46 PM

Amateur Engineer Figures Out Why His Kindle Randomly Restarts

Quote:

The lit case which retails for $59.99 uses gold hooks which supply power to the light bulb so that you can read on the go. Gizis figured out that the non-lit case uses two black painted hooks to attach the Kindle to the leather case. At first, these hooks conduct no electricity because the paint blocks it but as the case sees more wear and tear, the paint starts to chip off. And because this is where the light would get its electricity from, Gizis made the leap in logic that maybe it's siphoning off power from the device, causing all of the power downs and headaches.

"So out came the handy-dandy Radio Shack multimeter, set to measure resistance," said Gizis. "Depending on your contact you can see some pretty low values, which imply a pretty good connection between the two. This is why the Kindle crashes. Once a bit of paint has rubbed off the hooks, power starts flowing through the cover, leading to brownouts; the CPU does not get enough juice to operate properly and ends out either hung or rebooting!"

Wasn't this only happening with the WiFi version?

FF2 · 12-21-2010, 09:46 PM

We need more info (g)

Somone on another forum actually removed the plastic spine plate that holds those hooks. There was NOT physical metal/wiring connection between the hooks. So where that power is going in an incomplete circuit would be anybody's guess. The other suspicion is that once the insulation has worn from the hooks, static electricity can jump from the case (felt) or body (door knob shock) into the kindle.

It would be nice if Amazon actually id's the problem.

Teddman · 12-21-2010, 10:10 PM

Simply coat the metal hooks with a liberal amount of nail polish. Instant insulation.

Pushka · 12-21-2010, 10:42 PM

Amazon are refunded people where the covers are causing the issue. They acknowledge there is a problem with the non lighted covers.

jphphotography · 12-21-2010, 10:48 PM

If the two hooks aren't connected in the spine then it's possible that it could still be allowing an entry point for ESD, static builds up in everything and a little zap could easily cause the device to reset. Just my 2¢

dmalovic · 12-22-2010, 05:06 AM

People, the guy is jumping to conclusions and does not know what he is doing. I cannot believe that journalists are buying it!

He holds the multimeter probes by the metal prongs, effectively measuring the resistance of his arms and hands. The readout says 2 MEGA OHMS, not ohms as well. None of the people commenting on the above article even caught that?!

Doug Huffman · 12-22-2010, 07:56 AM

The amateur engineer uses amateur logic. If the conclusion is not falsifiable then it's not science or engineering.

Tiersten · 12-22-2010, 09:21 AM

What dmalovic said. A reading of 2M is because he is touching the probes with his fingers. Even he wasn't, a 2M resistance isn't going to cause the brownouts he claims are the reason the Kindle crashes/reboots.

Gripping the probes of a multimeter here I'm getting around 2.5M. The value will be different for each person and will be massively affected by how dry your skin is.

Whilst the hooks may possibly be the cause of the problem, it isn't for the reasons the author states. If you look at the original blog post, it seems to have reverted to mostly an advert for their product now and has had all of the cover related details removed.

Tiersten · 12-22-2010, 09:21 AM

Quote:

Originally Posted by Teddman

Simply coat the metal hooks with a liberal amount of nail polish. Instant insulation.

The nail polish would flake off very quickly.

shrik · 12-22-2010, 10:09 AM

So if I used a non-Amazon cover for my Kindle, I wouldn't experience the random restarts?

Tiersten · 12-22-2010, 10:33 AM

Quote:

Originally Posted by shrik

So if I used a non-Amazon cover for my Kindle, I wouldn't experience the random restarts?

If the theory about the hooks affecting it in some way is correct then any case that doesn't use those hooks shouldn't cause this. The theory hasn't been proven yet though and Amazon haven't confirmed anything either.

emalvick · 12-22-2010, 11:02 AM

I'm an engineer (not electrical though), and I would think that if there was a short, we'd have to have some connection between the hooks, which of course would have a lot less resistance than reported. More important, we should be able to measure a current or voltage. Everything has a resistance; it's the voltage or current that indicates a complete circuit or short.

What would be interesting is to experiment with a lighted cover (wish I had one at the moment) and see if we could recreate the brown outs/restarts... i.e. prove that it is the cover causing issues. Unfortunately, these may not be the ideal experiments (my electrical knowledge is relatively rudimentary). The first two items would seem similar to what is happening with the unlighted covers, yet they won't cause shorts. Item 3, would create a short, and that is something you do at your own risk.

1) disconnect one hook from the cover or isolate/insulate it to break the circuit. You might need to try this both ways since it would matter in a DC (battery based) circuit which end is + and which is -. (one could use nail polish and then quickly scrape it off after the test is complete.

2) disconnect the light bulb (if possible) and see if that breaks the circuit or causes any restart... If there is a switch, you'd want to make sure it is set for on for the test to work (i.e. try to run power through the missing bulb.)

3) This is something you do at your own risk and that is create a short using wire... If I was actually an electrical engineer (see my disclaimer at the top), I might actually try what I am thinking, but I'd hate to ruin my Kindle purposely creating a short.

As for the unlighted covers. The best solution to fixing a bare contact maybe to get a metal paint or other type of coating that is a bit more durable than nail polish. The key though is making sure it isn't too thick. The hook needs to be able to fit in the device. You also want to be sure it is dry.

As far as Amazon goes, they should be making these hooks out of plastic, nylon, etc. Something to guarantee that electricity isn't flowing.

FF2 · 12-22-2010, 11:15 AM

What needs to be done is more publicity that Amazon would have to respond to as to what is causing this problem. It appears that they have finally acknowledged there is a poblem but have not specified what it is. Obviously, this is no where near the issue of Toyota and engine surges or brakes failing so we may never know the cause.

The question is can those hooks be made out of a non-conductive material that when as thin as needed can fit into the slots and not break or crack. Or can they provide some kind of ground that shunts what might be static away from the hooks and into the case somehow/somewhere. Carbon fiber might conduct electricity.

OtterBooks · 12-22-2010, 01:46 PM

I was sad to see my Amazon cover go. If they release a new one corrected for the issue, I would even consider a re-purchase. They offered me a lighted one without additional cost, but I prefer the unlit cover.

mldavis2 · 12-22-2010, 02:08 PM

My solution, offered on multiple other threads is to turn the K3 off to a blank screen (5 seconds of the power switch) before engaging the hooks. Do not use the K3 while hooked into the unlighted cover. Remove the K3 before turning it back on (takes 2 seconds). I am keeping my two K3's and both unlighted covers. It's a no-brainer unless you absolutely MUST use the K3 while in the cover, or you absolutely cannot spare the 5 seconds to blank the screen before placing the K3 in the cover. Restart is the same as from the screensaver. I have done this multiple times over the past week with no problems of any kind.

12-22-2010, 11:02 AM	#12
emalvick Groupie Posts: 166 Karma: 5358 Join Date: Aug 2010 Location: Davis, CA Device: Kindle 3	I'm an engineer (not electrical though), and I would think that if there was a short, we'd have to have some connection between the hooks, which of course would have a lot less resistance than reported. More important, we should be able to measure a current or voltage. Everything has a resistance; it's the voltage or current that indicates a complete circuit or short. What would be interesting is to experiment with a lighted cover (wish I had one at the moment) and see if we could recreate the brown outs/restarts... i.e. prove that it is the cover causing issues. Unfortunately, these may not be the ideal experiments (my electrical knowledge is relatively rudimentary). The first two items would seem similar to what is happening with the unlighted covers, yet they won't cause shorts. Item 3, would create a short, and that is something you do at your own risk. 1) disconnect one hook from the cover or isolate/insulate it to break the circuit. You might need to try this both ways since it would matter in a DC (battery based) circuit which end is + and which is -. (one could use nail polish and then quickly scrape it off after the test is complete. 2) disconnect the light bulb (if possible) and see if that breaks the circuit or causes any restart... If there is a switch, you'd want to make sure it is set for on for the test to work (i.e. try to run power through the missing bulb.) 3) This is something you do at your own risk and that is create a short using wire... If I was actually an electrical engineer (see my disclaimer at the top), I might actually try what I am thinking, but I'd hate to ruin my Kindle purposely creating a short. As for the unlighted covers. The best solution to fixing a bare contact maybe to get a metal paint or other type of coating that is a bit more durable than nail polish. The key though is making sure it isn't too thick. The hook needs to be able to fit in the device. You also want to be sure it is dry. As far as Amazon goes, they should be making these hooks out of plastic, nylon, etc. Something to guarantee that electricity isn't flowing. Last edited by emalvick; 12-22-2010 at 11:28 AM.

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12-21-2010, 09:46 PM	#2
FF2 Wizard Posts: 1,105 Karma: 1025784 Join Date: Oct 2010 Device: WiFi Kindle3	We need more info (g) Somone on another forum actually removed the plastic spine plate that holds those hooks. There was NOT physical metal/wiring connection between the hooks. So where that power is going in an incomplete circuit would be anybody's guess. The other suspicion is that once the insulation has worn from the hooks, static electricity can jump from the case (felt) or body (door knob shock) into the kindle. It would be nice if Amazon actually id's the problem.

12-21-2010, 10:10 PM	#3
Teddman Addict Posts: 242 Karma: 695 Join Date: Jun 2009 Device: Sony PRS-505	Simply coat the metal hooks with a liberal amount of nail polish. Instant insulation.

12-21-2010, 10:42 PM	#4
Pushka Wizard Posts: 1,119 Karma: 1019140 Join Date: Oct 2009 Location: Australia Device: kindle, Ipad, Iphone, Nexus and PPW	Amazon are refunded people where the covers are causing the issue. They acknowledge there is a problem with the non lighted covers.

12-21-2010, 10:48 PM	#5
jphphotography Zealot Posts: 107 Karma: 27246 Join Date: Sep 2010 Location: Saskatoon SK, Canada Device: Kindle 3 6" 3G + wifi, Sony PRS-300, iTouch 4G, Galaxy S Vibrant	If the two hooks aren't connected in the spine then it's possible that it could still be allowing an entry point for ESD, static builds up in everything and a little zap could easily cause the device to reset. Just my 2¢

12-22-2010, 05:06 AM	#6
dmalovic Member Posts: 20 Karma: 234 Join Date: Dec 2010 Device: Kindle 3	People, the guy is jumping to conclusions and does not know what he is doing. I cannot believe that journalists are buying it! He holds the multimeter probes by the metal prongs, effectively measuring the resistance of his arms and hands. The readout says 2 MEGA OHMS, not ohms as well. None of the people commenting on the above article even caught that?!

12-22-2010, 07:56 AM	#7
Doug Huffman Banned Posts: 102 Karma: 7860 Join Date: Nov 2010 Location: Washington Island, across Death's Door, Wisconsin, USA Device: KINDLE 3 WiFi	The amateur engineer uses amateur logic. If the conclusion is not falsifiable then it's not science or engineering.

12-22-2010, 09:21 AM	#8
Tiersten Guru Posts: 987 Karma: 8641 Join Date: Aug 2010 Device: Kindle 3G+WiFi	What dmalovic said. A reading of 2M is because he is touching the probes with his fingers. Even he wasn't, a 2M resistance isn't going to cause the brownouts he claims are the reason the Kindle crashes/reboots. Gripping the probes of a multimeter here I'm getting around 2.5M. The value will be different for each person and will be massively affected by how dry your skin is. Whilst the hooks may possibly be the cause of the problem, it isn't for the reasons the author states. If you look at the original blog post, it seems to have reverted to mostly an advert for their product now and has had all of the cover related details removed.

12-22-2010, 10:09 AM	#10
shrik Member Posts: 17 Karma: 10 Join Date: Nov 2010 Device: Nexus 7 Wifi 32 GB	So if I used a non-Amazon cover for my Kindle, I wouldn't experience the random restarts?

12-22-2010, 11:15 AM	#13
FF2 Wizard Posts: 1,105 Karma: 1025784 Join Date: Oct 2010 Device: WiFi Kindle3	What needs to be done is more publicity that Amazon would have to respond to as to what is causing this problem. It appears that they have finally acknowledged there is a poblem but have not specified what it is. Obviously, this is no where near the issue of Toyota and engine surges or brakes failing so we may never know the cause. The question is can those hooks be made out of a non-conductive material that when as thin as needed can fit into the slots and not break or crack. Or can they provide some kind of ground that shunts what might be static away from the hooks and into the case somehow/somewhere. Carbon fiber might conduct electricity.

12-22-2010, 01:46 PM	#14
OtterBooks Wizard Posts: 1,262 Karma: 2979086 Join Date: Nov 2010 Device: Kindle 4, iPad Mini/Retina	I was sad to see my Amazon cover go. If they release a new one corrected for the issue, I would even consider a re-purchase. They offered me a lighted one without additional cost, but I prefer the unlit cover.

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12-22-2010, 02:08 PM	#15
mldavis2 Coffee Nut Posts: 410 Karma: 298350 Join Date: Oct 2010 Location: Missouri Device: Kindle 3; K4PC; Calibre	My solution, offered on multiple other threads is to turn the K3 off to a blank screen (5 seconds of the power switch) before engaging the hooks. Do not use the K3 while hooked into the unlighted cover. Remove the K3 before turning it back on (takes 2 seconds). I am keeping my two K3's and both unlighted covers. It's a no-brainer unless you absolutely MUST use the K3 while in the cover, or you absolutely cannot spare the 5 seconds to blank the screen before placing the K3 in the cover. Restart is the same as from the screensaver. I have done this multiple times over the past week with no problems of any kind.