[Q] (Q) Peculiar Battery Issue - Acer Iconia A500

The other day, my A500 started doing something weird during charging. when plugged in, it shows as charging via the hardware light AND the os itself. But, it wont charge. The only plus side here is that it will hold what it has while plugged in. I have it holding steady at 14%. Firstly, I tested the charger and it puts out a solid 12.0-12.1 volts, so that is fine. I have disassembled the tablet and checked all leads from the 12v in plug and all are fine and reading 12v at the board connection point. Inspection of battery shows no loose wires, and also has no bloat or noticeable issues. I have blown it all out and cleaned with 95% alcohol. All have no effect. SO, on to possible software issues. What can I check for here? Possible bootloader or other software failure? Any ideas would be greatly appreciated. Thanks.

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Help, my Hermes pretends to be dead

i woke up this morning, and my htc8525, which had just been sitting on a table for a couple days, was off. battery ran out, i thought. i plugged it in to the wall adapter and not even the charging light came on. i plugged it in to a usb cord on my laptop and still no love. i cleaned the battery, charger and sim contacts with rubbing alcohol, still nothing;
i have not flashed it or updated software in it in over 2 months.
any suggestions on what could the problem be or how to fix it!?!?
thanks!
Try with another battery, sometimes batteries are hard to kickstart when they are completely drained.
Mmmm. Yes the charging circuit can get temperamental if the battery runs below 10%. But in that circumstance the Red LED will come on when the charger is connected.
The likely situation is that either:
1
The battery is completely flat and co-incidentally a pin is bent in the usb socket (thus preventing charging) - a somewhat unlikely co-incidence.
2
The internal on-board fuse is blown - this is actually not that uncommon.
You can see a pic of the fuse location in the Service Manuals section here:
www.mikechannon.net
Mike
I have made the assumption that the charger is operating normally.
similar problem here:
When connected (charger or USB cable) Red LED 'no charning' comes on.
How can I solve this problem and force the device to charge?
Thanks in advance
edit: I've downloaded Service Manual and tried to charge it - it's been almost 4 hours now, and Hermes is still dead, red LED still on (not amber)
To be clear, if the device shows a red LED then it's a charging circuit problem or a faulty battery. If no LEDs light up then it may be the fuse problem, USB connector, or battery connector block problem.
For situations where you get the red LED try these:
http://forum.xda-developers.com/showpost.php?p=1077622&postcount=6
Mike

Need help troubleshooting, dead rk3066 tablet

Hello,
I need help with my new tablet.
Model is Allfine Fine10 Yoy.
Specs:
Rockchip RK3066, 1.6GHz, Cortex A9 dual core; GPU: Mali 400 MP4
Android 4.1
1GB (DDR3)
16GB Nand Flash
10.1 Inch / IPS
Battery: 7800mAh
It is not so old, about 5 months. Few days ago I have left it to charge overnight (it usually takes 4-5 hours to charge so I always charge it overnight) and in the morning it could not turn on. It is dead, no signs of life. I checked maybe it did not charge, so I changed power socket and tried again.
I can not charge it via USB so I can't test that.
There is not sign of life when connected to PC, adb list's no devices.
There is no sign of life after holding power/lock button for a long time and there is not signs after holding restart button.
It came factory rooted, I've never updated/flashed or anything.
I have not noticed any troubles so far, no lags, no freezing, no overheating.
Are you familiar with debug method for this kind of tablet?
What should I do, what test to make?
Can you help me debug this, please.
Thank you.
cheap china tablets are easy to open up. just pry the back cover off carefully and put a volt meter on the battery. its probably dead.
check your power supply first, it might have croaked too.
Would it be possible to run tablet with removed battery, straight off adapter to check is it working?
mrnjau said:
Would it be possible to run tablet with removed battery, straight off adapter to check is it working?
Click to expand...
Click to collapse
Possibly, at least some part of startup.
Most device processors will start up if they notice power coming from somewhere.
At some point try will try to access the state and source of power.
If they notices that the battery is really dead (that is, the power is only from USB) they will shut down and go into charge-only mode.
It may be more likely that your battery is charged and the processor got wedged somehow.
Disconnect from USB, open the back, disconnect the battery and reconnect it.
Renate NST said:
Possibly, at least some part of startup.
Most device processors will start up if they notice power coming from somewhere.
At some point try will try to access the state and source of power.
If they notices that the battery is really dead (that is, the power is only from USB) they will shut down and go into charge-only mode.
It may be more likely that your battery is charged and the processor got wedged somehow.
Disconnect from USB, open the back, disconnect the battery and reconnect it.
Click to expand...
Click to collapse
Thank you for your reply,
I've precedeed as you sugested.
Solder is pretty hard on battery connection, so I unsoldered just one (negative wire, red one) and pluged it to charger and try to start it. I undsolderd just one because I don't want heat to ruin something and I guessed it should be enough to try this.
It still shows no signs of life.
However I've noticed something, when re-soldering red wire I have noticed that there is a spark when wire is near the solder point. So, there is some power in battery.
Any idea how to proceed? I still don't have multimeter to test battery voltage so that will have to wait.
Thanks once again.
Oh, sorry, I thought that the battery was on a connector.
That makes life easier than soldering.
The red wire(s) are always the positive.
The black wire(s) are always the negative (ground).
Any other color wires on a battery are thermistor, id sense or communication.
Yes, finding/borrowing a voltmeter is the next step.
Renate NST said:
Oh, sorry, I thought that the battery was on a connector.
That makes life easier than soldering.
The red wire(s) are always the positive.
The black wire(s) are always the negative (ground).
Any other color wires on a battery are thermistor, id sense or communication.
Yes, finding/borrowing a voltmeter is the next step.
Click to expand...
Click to collapse
Renate, I hope you still follow this topic.
I'm sorry for 2 months without updates, I've waited for some time for parts from China.
So, what have I done so far...
1) Get multimeter.
2) Test battery.
Battery is designated as 3.7V, however output is 4.15 - 4.16 V.
I've presumed this is fine.
3) Test the charger.
Charger is designated on 5V and 3A. I've tested voltage, it is fine. However ampers dance between 0.5A and 3.5A. I've presumed that charger is faulty, so I've ordered new one. Generic 5V, 3A charger.
4) Put it back together, re-solder the battery and connect charger. Test again.
Voltage on battery connectory is same as before - 4.15V.
After 20min there is no change in battery temperature (source: my fingers), however power jack where new charger is connected is getting warm, but not too warm.
Tried to power it on, no signs of life. Tried holding restart button for forewer, no sign of life.
I'm out of ideas.
3 Amps is a heck of a charger.
Where did that come from? Is it stock?
You have a little round coaxial connector for the charging input on the tablet?
There's no reason that it should be drawing 3 amps or anything getting warm.
The battery is fully charged.
There could be a high resistance in the battery protection module so that it looks charged but can't actually supply any current when called upon.
There's a USB connector on this too?
And nothing appears when you connect a USB cable to it?
I wouldn't expect ADB, but maybe a bootloader.
Run devmgmt.msc when plugging it in and see if anything at all shows up.
Renate NST said:
3 Amps is a heck of a charger.
Where did that come from? Is it stock?
You have a little round coaxial connector for the charging input on the tablet?
There's no reason that it should be drawing 3 amps or anything getting warm.
The battery is fully charged.
There could be a high resistance in the battery protection module so that it looks charged but can't actually supply any current when called upon.
There's a USB connector on this too?
And nothing appears when you connect a USB cable to it?
I wouldn't expect ADB, but maybe a bootloader.
Run devmgmt.msc when plugging it in and see if anything at all shows up.
Click to expand...
Click to collapse
Stock charger is 3A, so I bought with indetical specs. My research showed that a lot of chinese tabs use 3A chargers (Ainol Hero, etc..)
Yes, charger connector is 2.5mm "needle".
Some 30min after I posted this area around connector and speaker on motherboard got very very hot, I almost injured myself by touching it. So I've disconnected it.
No, nothing on USB. I've mentioned it in my first post, there are no signs of life on adb. Or "dmesg", which should list something even if device was bricked.
Um, are you sure that the polarity of the supply is correct?
For coaxial plugs the center is usually positive.
If it got that hot you probably have blown something.
Renate NST said:
Um, are you sure that the polarity of the supply is correct?
For coaxial plugs the center is usually positive.
If it got that hot you probably have blown something.
Click to expand...
Click to collapse
http://www.amazon.com/2000mah-Adapt...6-6172141?ie=UTF8&refRID=1AED4Q5XRX7QS8JJ91Y9
This is that kind of power connector, 2.5mm. Are we talking about the same thing? Is is possible for this kind of connectors to have non-standard polarity.
Maybe nothing is blown, I would smell that. Maybe there just hi resistance somewhere along the line.
Well, if it's the same charger and it used to charge then the polarity must be ok.
Still, something is not happy.
You should have been able to get it working with just the battery.
The DC input should not be getting hot.
I can only say so much from this distance.
Renate NST said:
Well, if it's the same charger and it used to charge then the polarity must be ok.
Still, something is not happy.
You should have been able to get it working with just the battery.
The DC input should not be getting hot.
I can only say so much from this distance.
Click to expand...
Click to collapse
I can't find any info on ampers and battery. I can't measure any amps coming out of battery, that's strange. I don't know much about this but should not battery put up some ampers?
Yeah, I understand that DC port should not get hot. Only 2 options.
1) Charger (the new one) is putting up too much electricity, to many amps that is.
2) There is something faulty on DC port or around it and causes too much resistance and thus heat.

Completely dead and unresponsive Nexus 4 after voltage spike while charging in car

So yesterday, my old car's voltage regulator went haywire, and blew the car's main fuses after a couple of seconds.
I was charging my N4 during this incident with a cigarette lighter thingy and was holding aprox. 10% batttery charge.
The N4 is now 100% unresponsive. No amount of pressing any key combination for any amount of time does anything at all.
I have also tried charging it with a generic USB charger for a couple of hours, to no effect.
After that, I tried charging it with my computer's USB3 port for a couple of hours. This warmed up the phone a bit on the back, so it seems the ingoing current is doing something in there.
I am not getting a red LED indicator as most other people seem to be getting.
i fear something important was simply fried inside the phone, but I don't want to give up yet!
- Does anyone have any ideas what else I could try out?
- Are there maybe some small fuses inside the N4 that might be burned due to the voltage spike? Could I maybe replace or bridge them?
- could replacing the battery maybe revive the phone? If so, how could I test if getting a replacement battery will be worth it? Maybe temporarily wiring a compatible voltage to board?
http://www.reddit.com/r/nexus4/comments/29gkfj/usb_power_surge_killed_nexus_4/
Does this help?
LooieENG said:
http://www.reddit.com/r/nexus4/comments/29gkfj/usb_power_surge_killed_nexus_4/
Does this help?
Click to expand...
Click to collapse
Cool! I must have missed that the USB charging stuff is on a seperate board when i stepped through the N4 teardown!
Do you know if wireless charging goes through this board, too, or would it be using a separate circuit - i.e. should I head over to a friend's and test if I get SOME reaction from the phone when wirelessly charging?
Also: what worries me is that, as i mentioned, the phone's back is getting quite warm when charging it via USB3, so I am afraid that the charge is actually getting to the battery (vs. being stopped at a burnt fuse)

Dead charging circuit?

Hi everyone;
I've having an interesting time with my nexus 7 (2012 wifi 32gb).
Before I left on vacation I couldn't get the thing to charge. Looking at the usb port I thought it had become to damaged to make a good connection. So while I was away I ordered a new port assembly. Installed that and still no charging.
Oh the battery cell voltage had gone down to 2.2V so it's in a sleep mode. No problem used a proper lion charger to trickle charge it back to life then further to about 3.8V.
At that point it boots up though the optimization took the charge down to 2% so couldn't do more testing but clearly it worked just fine. However the thing won't charge. Plugging it in to USB it does detect the connection but does not draw any current (as shown by a usb voltage/current monitor). It will show the charge screen, go through 3 cycles of the battery filling animation then shut off.
I check and the voltage is getting from the usb cable into the connector. I traced the ribbon cable from the IO board up to the motherboard and at the other end I also get a nice 5V reading. Clearly the connection from the USB to the device is being made no problem.
At this point I am thinking that maybe I blew the charging circuit. When I was orignally trying to get it to charge before leaving I was applying all kinds of stress to the connector to get it to charge and there was a few times where I think I shorted it (usb monitor showed >3A and the device reset).
Anybody have another theory?
At this point I can't really use it as charging the cell externally is dangerous and not convenient. At this point from what I have seen with my testing and on here if I want to use it I would have to apply 5V to the battery connector (sans battery) which I haven't tried yet.

Dead YD206

So YD206 about a month old. Was connected to official yota charger (via a magnetic usb cable), noticed the plug at the phone end getting quite hot. Phone now essentially dead, wont boot, doesn't seem to charge. We also realised the charger had come out of the wall socket. But the yotaphone light was intermittently flashing on the charger.
Whilst I am inclined to blame the magnetic charging cable, is it possible for current to flow in reverse from phone to charger and essentially discharge the phone battery below acceptable levels?
Any advice on rebooting it (can't remove the battery like I would on a Samsung) so whats the procedure?
Just a follow up charger not the issue, it crashed in use and the power button became non-responsive, with the screen off, and the e-ink display on but also unresponsive. Did not turn on when connected to a charger. However when I connected it to my pc it did register in device manager as MTP device, so I knew it was still alive. Removed the sim and held the power button down for 10 seconds then it rebooted.
Hope this helps anyone else with a similar problem.
Failing that it would probably have to be left to discharge (might take a while if nothing is running) then powered back on with charger attached.
I have similar problem. My phone got hot while not charging (about 15% of battery) and crashed. Then forced reboot (hold power button for about 10 seconds) helped while phone was connected to Yota charger, battery was dead, but phone booted (EPD on, did not check rest) and got to about 81%. After removing it from charger, same thing happened again, no luck with forced reboot this time. Phone was blazing hot and did not respond, then crashed again. No response after connecting charger or forced reboot. Any experience with this issue appreciated.
SuperTukan said:
I have similar problem. My phone got hot while not charging (about 15% of battery) and crashed. Then forced reboot (hold power button for about 10 seconds) helped while phone was connected to Yota charger, battery was dead, but phone booted (EPD on, did not check rest) and got to about 81%. After removing it from charger, same thing happened again, no luck with forced reboot this time. Phone was blazing hot and did not respond, then crashed again. No response after connecting charger or forced reboot. Any experience with this issue appreciated.
Click to expand...
Click to collapse
It seems a battery issue. Have your Yotaphone a valid warranty?
casaprocida said:
It seems a battery issue. Have your Yotaphone a valid warranty?
Click to expand...
Click to collapse
I am not sure about my warranty, bought it off AliExpress, I guess I could try to send it to manufacurer (i heard Russia provides repair service).
EDIT ( t + 2 days): I managed to start my Yota again. I connected it to computer and after about 5 minutes, magic happened and phone started all by itself. I will try to find out more, will update this as soon as I find something
Man, you are more lucky than me, I have a dead yotaphone lying around here. It also died after connecting it to a bad power source.
In my case it was the usb-port of a monitor.
When I checked the usb-port with a cable with a volt/amp display I saw that it was going on and off very quickly.
But so I would say be careful where you connect your yotaphone to, it does not seem to handle weird power sources all too well.
tomgaga said:
Man, you are more lucky than me, I have a dead yotaphone lying around here. It also died after connecting it to a bad power source.
In my case it was the usb-port of a monitor.
When I checked the usb-port with a cable with a volt/amp display I saw that it was going on and off very quickly.
But so I would say be careful where you connect your yotaphone to, it does not seem to handle weird power sources all too well.
Click to expand...
Click to collapse
I actually thought about burning charging circuitry a lot. I wonder, if you would be able to test wireless charging. With some luck, it is independent enough to not be affected by burning micro usb charging route (depends where high voltage safety is implemented). If this make any sense to you, please give this a try (I think IKEA is place to go, they should have working wireless chargers in their model setups) and report back. If I am wrong in any aspect, I'd appreciate any correction with explanation.
SuperTukan said:
I actually thought about burning charging circuitry a lot. I wonder, if you would be able to test wireless charging. With some luck, it is independent enough to not be affected by burning micro usb charging route (depends where high voltage safety is implemented). If this make any sense to you, please give this a try (I think IKEA is place to go, they should have working wireless chargers in their model setups) and report back. If I am wrong in any aspect, I'd appreciate any correction with explanation.
Click to expand...
Click to collapse
Sorry for the late reply, did not see the quote, but it does not work with wireless charging either. I think the battery still has a lot of charge too. Thing is that the Motherboard also gets hot after a while when I try to charge it. I'm pretty sure my motherboard is dead. But I have another Yotaphone now, so maybe in the future I will test with every separable part replaced.
I use the charger from my iphone. It works great, although with the yotacharger also works well. Attention that I have a YotaPhone YD201 with Russian base and european compilation. Like I said the Iphone charger works great and doesn't warm my Yotaphone 2 . It might be a solution for your problems with charging.

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