MobileRead Forums - View Single Post - Amateur Engineer Figures Out Why His Kindle Randomly Restarts

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.

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.