How can I fix a completely Dead Nexus 7?

[AC Question]

Completely Dead Nexus 7

Went to use my Nexus 7 and have a black screen. I tried to charge it using my PC, nothing. I tried to charge it using a wall charger, still nothing. I tried to hold down the power button, nothing. I tried to hold down the power & volume button for 30 seconds, still nothing. Not sure what else to try. Can someone please help? I am a little afraid to take the back off for fear of breaking one of the plastic tabs.

 

[natehoy]

Re: Completely Dead Nexus 7

How long did you leave it on the charger?

It COULD be that the battery discharged to the point where the battery management system (BMS) tripped the battery into "safety mode", where the battery is not allowed to discharge at all until it reaches a much higher voltage level. This is designed to keep a Lithium battery from dropping below the voltage necessary to maintain the cells (at which point the battery goes from "mostly dead" to "dead dead" and the only thing you can do is go through its pockets for loose change).

If your battery is "mostly dead" (in safety mode), plug it into a wall charger, and walk away. Leave it alone for at least a few hours. If the BMS is able to recover the battery, it's going to charge it really, REALLY slowly out of safety mode to prevent damage. You will not see any visible signs of anything happening.

If after 12 hours there have been no changes, then the charger was unable to recover the battery and it's "dead dead". You MIGHT be able to "kick start" it by bypassing the BMS and applying charge to the cells directly, but that's a good way to get yourself hurt unless you know exactly what you are doing.

Of course, the problem may not be the battery. It could be the charging circuit, or any one of a number of things. But if it's the battery, then your best bet is to just give the BMS some energy and a little time to work its magic.