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I recently left my Cingular 8125 in Bootloader mode over night, connected to my PC not knowing that it couldn't charge while in that mode. I woke up, and couldn't turn it on; I eventually found out that the battery couldn't charge while in Bootloader mode.
The only solutions that I've seen posted are to: (A) Get another charged battery, (B) Charge your battery in a working Wizard
Both solutions aren't possible for me at the moment... what I needed to know is if there is a way to charge using some funky wiring rig using standard AA batteries to power it for about 7-10min. or so.
Cut one end off an old usb cable. Then plug the usb cable into your computers usb port and touch the black wire to the (-) on the batt and the red wire to the (+) on the battery. It takes a few minutes, but the battery will charge. Then put the battery back in the phone and boot into the os. Then charge the phone as usual.
Jeff
You can jump some wires to your battery from a battery charger to get some power to your battery --- need 5.7 volts -- positive to positve, negative to negative but I would not recommend doing this. Your battery is a lithium Ion which takes a special charge. Take it to a Cingular Store and ask the clerk if they could just charge it up in another phone for a couple of hours. I'm sure they won't mind.
Lithium Ion batteries are fussy about how they are charged, so its best to do it in another phone or a charger made for your battery.
Cheers!
Thank you guys sooooooooooo much for the info.
You have no idea how important this is.
EDIT: I stripped the USB cable, the outer wire is silver and there is quite a bit of it... there are four wires encased in the middle: one black, one brown, one red, one orange... I do not know which wires to connect to the pads on the battery.
Can someone verify that the Nexus 7 can operates perfectly fine with the battery removed and only powered by the USB cable? I've read some threads eluding to this, but no one has confirmed. Mine is in the dash of my car so i cant verify this myself. If someone can. that would be amazing! Thank you.
look at the thread right below yours.
Old Guy said:
look at the thread right below yours.
Click to expand...
Click to collapse
I saw that thread, i was still a bit confused as they were talking about USB DAC and other devices hooked up to me.
I want to make sure data can still be transferred from the same USB cable and such.
Yes, it's possible, but has some side-effects
Yes, it's possible to power the Nexus 7 without battery from a USB-cable, but it involves sending power directly to the battery connection inside the Nexus 7, and it seems to have some side-effects.
The battery is a one-cell lithium polymer, which has a max charge of 4.23 V. I hoped the Nexus wouldn't fry when connecting 5 V, and it has worked fine the few minutes I've tested it. No smell of burnt electronics
Here is what I did:
Tear off the tape around the battery cable. You'll see it's soldered to a pcb-board, and the two black and two red wires are soldered together. The two wires in the middle is probably some kind of data-connection to the battery. Will investigate this further later.
Then I soldered loose the cables, so I could use the battery-connector, and soldered both red and black wires to red and black wires in a USB-cable. Drilled a hole in the back-cover right below the NFC-antenna. The back-cover is filled with all sorts of antennas, so scratch carefully with a knife before drilling. Attached some pictures of the process.
Side-effects I've noticed so far:
- It thinks the battery is at 0% and not charging.
- The clock is reset when you turn off the power. But if you have internet it will update from NTP within a minute or so.
- My computer (OS X) can't detect it anymore. So I suspect it doesn't work in USB device-mode anymore, but I'm able to connect a USB-keyboard with an OTG-cable, so it seems to work in host-mode.
Does anyone else have any experience with this, or any ideas why it doesn't work in device-mode? I'm considering adding a small connector so I can use the two extra wires from the battery to the data-wires of the USB-cable (and disconnect when not in use), and then solder a USB female cable to the original battery. That way I can (hopefully) connect the Nexus 7 to my computer when needed, and possibly analyze what the two extra wires is actually used for.
I have CM for Android 4.2, and Timur's USB-rom, but it's probably not needed for this hack, and I will probably install a stock rom if I get this working properly.
Be careful, and don't blame me if you fry your Nexus (or anything else). Be sure to turn off any fast-charge hacks when the battery is disconnected.
Old Guy - look at the thread right below yours
Click to expand...
Click to collapse
Threads are sorted by last post in each thread, so it's impossible to find which one you are referring to. Do you have an url?
Theory worked
I managed to connect the Nexus 7 to my computer again
I'm considering adding a small connector so I can use the two extra wires from the battery to the data-wires of the USB-cable (and disconnect when not in use), and then solder a USB female cable to the original battery. That way I can (hopefully) connect the Nexus 7 to my computer when needed, and possibly analyze what the two extra wires is actually used for.
Click to expand...
Click to collapse
Can confirm that this works. I didn't have any small connectors, so I hot-glued one header-pin and a female connector for a header pin on the data-wires in the USB-cable. Doesn't look good, but it works
When I have it in the car, I disconnect the header-pins on the USB-cable, and connect it to an USB power-source. When I need to connect it to the computer, I connect the header-pins and connect the battery (with the female USB-cable), and a regular USB-cable to the computer.
Sorry to bring up an older thread, but it sounds like the White and Yellow wires of the battery are for data?
if so, if I applied 3.7-4.2 volts on the battery connection and then still had a 5v connection on the USB would this work?
I would like to use Timur's ROM, and have power applied when my car is off (fixed install) for deep sleep and then apply the 5v when the car is on to bring it from the deep sleep. the issues would be faking it to not charge which I am guessing would mean to set the battery input to 4.23 volts to show as being fully charged. then when key on, the 5v would take over and you would still have the 4.23 applied at the battery connection ( probably have a diode on the + side to keep from injecting voltage to that supply
Has any one completed something like this?
The problematic usb port finally gave up on my Nexus 7 (2012). I've opened up it up, connected the black and red wires from a cut usb cable to the 1st and 4th pogo pins without removing the battery. Now charging's fast and stable..
Added: Tried 5v2a charging, it doesn't melt anything.. Fully charged in just slightly over1 hour.
This thread has been great help and a motivator for wiring my Nexus 7 to do a (permanent) dash install.
I've just removed the battery and wired it to a Pico-Box X5-ATX-180 carputer PSU with an adjustable voltage converter in-between to get around 3.9 volts to the tablet. Works great, but I found another drawback.
Like mentioned in a post before me, the battery status will show 0% which I thought wouldn't be too big of a problem. However, at the moment there is an Android update (4.4.3) available and when I try to update it first tells that the battery is too low and that I should connect a charger. So I did, but then it tells me too "wait for the battery to charge sufficiently".
So for anyone reading this wanting to do the same, know that you won't be able to update Android without a battery connected.
I have attached a photo of the tablet running without a battery for those interested.
Rutjes said:
This thread has been great help and a motivator for wiring my Nexus 7 to do a (permanent) dash install.
I've just removed the battery and wired it to a Pico-Box X5-ATX-180 carputer PSU with an adjustable voltage converter in-between to get around 3.9 volts to the tablet. Works great, but I found another drawback.
Like mentioned in a post before me, the battery status will show 0% which I thought wouldn't be too big of a problem. However, at the moment there is an Android update (4.4.3) available and when I try to update it first tells that the battery is too low and that I should connect a charger. So I did, but then it tells me too "wait for the battery to charge sufficiently".
So for anyone reading this wanting to do the same, know that you won't be able to update Android without a battery connected.
I have attached a photo of the tablet running without a battery for those interested.
Click to expand...
Click to collapse
You could use the factory image to update your nexus 7. It's just a bit more work.
Rutjes said:
This thread has been great help and a motivator for wiring my Nexus 7 to do a (permanent) dash install.
I've just removed the battery and wired it to a Pico-Box X5-ATX-180 carputer PSU with an adjustable voltage converter in-between to get around 3.9 volts to the tablet. Works great, but I found another drawback.
Like mentioned in a post before me, the battery status will show 0% which I thought wouldn't be too big of a problem. However, at the moment there is an Android update (4.4.3) available and when I try to update it first tells that the battery is too low and that I should connect a charger. So I did, but then it tells me too "wait for the battery to charge sufficiently".
So for anyone reading this wanting to do the same, know that you won't be able to update Android without a battery connected.
I have attached a photo of the tablet running without a battery for those interested.
Click to expand...
Click to collapse
What did you use to get the voltage down to 3.9 volts?
the exact thread I've been searching for.
Just completed by initial installation and now troubleshooting various problems.
The biggest being this battery scenario. So from what I've read in this thread is to use a DC-DC power switcher PICO for carputers and run that to the battery leads. How is the boot time though?
I've read that with a low battery, the kernal during bootup takes longer for checks to occur?
I have an idea.....:
If we can switch 12VDC to 5VDC during switched (Key On Accesory) with a regulator.....
we should be able to do the same with a sepearate regulator to switch 12VDC to5VDC during constant (Key off) when the switch voltage is lost.
This would retain the time you mentioned gets lost. Also, how much mAh (current) do you get out of that PICO regulator to the battery leads? The TIMUR kernal for FI-mode wants 1800mAh at least. Currently I'm using a cigarette lighter DC-DC adapter that has 2 ports. (2.1A, and 1A). The Nexus 7 is currently connected to the 2.1A and my HUB is connected to the 1A.
any advice?
Thanks
rezmax said:
Just completed by initial installation and now troubleshooting various problems.
The biggest being this battery scenario. So from what I've read in this thread is to use a DC-DC power switcher PICO for carputers and run that to the battery leads. How is the boot time though?
I've read that with a low battery, the kernal during bootup takes longer for checks to occur?
I have an idea.....:
If we can switch 12VDC to 5VDC during switched (Key On Accesory) with a regulator.....
we should be able to do the same with a sepearate regulator to switch 12VDC to5VDC during constant (Key off) when the switch voltage is lost.
This would retain the time you mentioned gets lost. Also, how much mAh (current) do you get out of that PICO regulator to the battery leads? The TIMUR kernal for FI-mode wants 1800mAh at least. Currently I'm using a cigarette lighter DC-DC adapter that has 2 ports. (2.1A, and 1A). The Nexus 7 is currently connected to the 2.1A and my HUB is connected to the 1A.
any advice?
Thanks
Click to expand...
Click to collapse
Why go through all the trouble? Just snip off any USB cable and connect to the pogo pins.. This way, you can charge at pogo's speed with any wall charger and still bring your tablet anywhere.
Hi guys just wanted to report i used your trick on my nexus 7 and it worked perfectly!
I used this method to check if the problem was the battery or if the screen was dead and it turned out to be the battery!
Now i have another battery on the way from Ebay.
Thanks again good job!
Hi guys me again,
I want to update the software but it wont let me because battery is on 1% for ever.
BUT i was wondering, what would happend if i simultaneously plug in the mini usb to another usb charger?
would that create some sort of an insane weird circut and burn my tablet?
any thoughts?
thanks!
Im thinking to use the Nexus 7 in car without the original battery. Constant 4.2V from car battery via converter to nexus battery pins and using the usb with ignition to switch the tablet between sleep and normal state. One thing i would want to reuse is the temperature sensor in the Li-ion pack. Has anyone some idea if the two extra wires are directly connected to temp sensor or there is a circuit for it on the battery controller? If so how it could be reproduced so i could use this to monitor the temp in car for example or if anyone knows any usb dongles that i could use for monitoring external temp with android.
So now i hav tryed the nexus without the battery aswell. At first i applyed 5v directly to the little black battery connector. tablet worked but showed 0%. Then tryed desoldering the batteryback from the little circuit and applyed 5v to the actual battery connectors on the circuit. It shows 100% battery and works and also the temperature sensor is working. One issue is that i need to plug in the charger before connecting the circuit to the motherboard, maybe the charger im using is just too weak that cant get the voltage up or something. And another thing is that i left it plugged in for the night and now the percentage goes down slowly as it would be discharging. havent figured out why that is. Maybe someone has tackled this before also?
freakadell said:
So now i hav tryed the nexus without the battery aswell. At first i applyed 5v directly to the little black battery connector. tablet worked but showed 0%. Then tryed desoldering the batteryback from the little circuit and applyed 5v to the actual battery connectors on the circuit. It shows 100% battery and works and also the temperature sensor is working. One issue is that i need to plug in the charger before connecting the circuit to the motherboard, maybe the charger im using is just too weak that cant get the voltage up or something. And another thing is that i left it plugged in for the night and now the percentage goes down slowly as it would be discharging. havent figured out why that is. Maybe someone has tackled this before also?
Click to expand...
Click to collapse
You supplied power to the protection circuit? I'm surprised that worked.
The battery is probably going down because the protection circuit is designed to prevent over and under voltage. Since you're feeding it 5V and a lithium battery is supposed to max out at about 4.2V it must be trying to lower the voltage somehow. The percentage going down is probably nothing to worry about, but I'd strongly recommend connecting to the battery connector instead, and only connecting it like this when you need to have a certain percentage to do a system update etc. Also be careful with the bare battery, if the two pins short it could catch fire.
Hi i tried that works ,however it doesn't boot when powered i have to turn it on pressing power button,any idea why?
As a car dash its pretty useless now
Just a quick message that I have managed to power my nexus 7 2012 from a USB cable connected to the circuit board that was attached to my dead battery. Battery level indicator is permanently at 100%.
Sort of like the above it involves using the battery circuit board but it is disconnected from the battery.
Step 1: Strip back battery wrapping revealing the board attached to the connector cables (that connects to Nexus 7)
Step 2: Cut the metal strips going from the circuit board to the actual battery part
Step 3: Solder USB cable Positive wire to board pad labelled VP and Negative to pad VG(? not 100% on last one, but it's the other pad)
Step 4: Solder short wire from VP pad to other side of the board onto the ++ pad (that goes to the red wires then connector)
Step 5: Wrap board up with elec/other tape to avoid shorts
Step 6: Connect up and power on
Not sure why the last wire is needed but it didn't work for me without it.
Next step for me is to wire it to the onboard micro-usb
Where is the ++ pad ??
dribbleboy said:
Step 4: Solder short wire from VP pad to other side of the board onto the ++ pad (that goes to the red wires then connector)
Not sure why the last wire is needed but it didn't work for me without it.
Next step for me is to wire it to the onboard micro-usb
Click to expand...
Click to collapse
Where is the ++ pad mentioned in step 4 ? Can you post some pictures ?
Got a new nook simple touch- charged in for 24 hours - will not power up- has the same screen all the time "fully charge before first use".
Tried 4 different charges, cables and different PC's. Contacted Barnes & Noble support - talked me through all various software resets pressing buttons - nothing worked - then told me take it back to store. I cannot return the thing as live outside uk.
I have tried removing the battery by taking the thing apart , leaving battery disconnected for a few hours - reconnecting it but nothing works.
The LED light is always green when plugged into charger, from what i gather it should be orange when charging?
The battery also does not seem to be heating up when charging, i have touched it a few times to test its stone cold
Nothing happens when connected to PC either.
Does anyone know any reset procedure that i can try please as i am getting to the stage of throwing this thing into the bin?
it may just be a bad unit
If you have a voltmeter, see if you can measure a voltage across the red and black leads out of the battery.
The Nook will not boot up without a battery (on the USB obviously).
I haven't looked into whether it's a safety on the thermistor or what.
Renate NST said:
If you have a voltmeter, see if you can measure a voltage across the red and black leads out of the battery.
The Nook will not boot up without a battery (on the USB obviously).
I haven't looked into whether it's a safety on the thermistor or what.
Click to expand...
Click to collapse
Thanks i do have a voltmeter but there is no red black lead, there are 6 wires as in the image attached, do you know what the six wires are or is there anyway to find a pinout from them so i could meter it?
There's no other tricks to reset the battery is there i have heard sometimes the battery needs to be left unconnected for a few hours then reconnected but that didn't do nothing for me
Thanks
I see red, I see black.
The two red wires on the connector are positive.
The two black leads on the connector are negative.
The yellow and the green are for the thermistor to measure battery temperature.
A truly frozen Nook.
I finally got around to investigating fully the whole battery wiring on the Nook.
Some people have expressed interest in running a Nook without a battery.
Removing the battery and using USB power does not work.
As stated above, of the 6 wires, the two red are positive and the two black are negative.
The green wire is a battery ID.
This is a 30K ohm resistance to ground to indicate that the battery is plugged in.
The yellow wire is for battery temperature.
This is a NTC (Negative Temperature Coefficient) thermistor.
It has a resistance of about 10K ohms at room temperature, decreasing as the temperature goes up.
You can run your Nook without the yellow wire (thermistor).
(The battery temperature will be off.)
You do need the green wire (battery ID) to get the Nook to power.
If you want to run your Nook without a battery,
connect a 30K from green to ground (27K seems to work fine) and
connect a 10K from yellow to ground (just to be nice) and
feed the V+ battery with around 4V.
You might try feeding that with a diode voltage drop off the USB connector.
(I didn't try that.)
The screen shot indicates -40C for open and +40C for 5K ohms.
(Thanks to 160thehaven for the photo. I have no macro lens.)
Renate NST said:
If you have a voltmeter, see if you can measure a voltage across the red and black leads out of the battery.
The Nook will not boot up without a battery (on the USB obviously).
I haven't looked into whether it's a safety on the thermistor or what.
Click to expand...
Click to collapse
okay close to throwing this thing away, the light is always green. I think the battery is not charging. even though when plugged in i seem to be getting a voltage swing on the red and black wires.
Should i measure the voltage across the red and black wires when booting up the nook? with the usb disconnected
To make life easy, grab the ground off the metal cage for the SD card.
What's the voltage on the red with no USB connection?
When you connect the Nook to your PC does it ever say, "Found new device OMAP3630"?
The question, is the processor powering up at all?
Is it doing the primary bootloader?
Is it doing the secondary bootloader?
If you had a kernel console, it might tell you what's up.
Just for yucks, what's the voltage on the yellow and green test points?
Does it pulse every few seconds?
his eedolsi
Renate NST said:
To make life easy, grab the ground off the metal cage for the SD card.
What's the voltage on the red with no USB connection? i will test this now
When you connect the Nook to your PC does it ever say, "Found new device OMAP3630"?
yes it does and it looks for the driver and keeps connecting and reconnecting
The question, is the processor powering up at all? how would i know this
Is it doing the primary bootloader? how would i know this
Is it doing the secondary bootloader? how would i know this
If you had a kernel console, it might tell you what's up.
Just for yucks, what's the voltage on the yellow and green test points?
Does it pulse every few seconds?
Click to expand...
Click to collapse
yes when plugged in the light is solid green but then pulses orange every few seconds
160thehaven said:
yes when plugged in the light is solid green but then pulses orange every few seconds
Click to expand...
Click to collapse
Oh, I was asking if the green and yellow test points pulse.
What's the voltage on them?
Mdevai 155
Renate NST said:
Oh, I was asking if the green and yellow test points pulse.
What's the voltage on them?
Click to expand...
Click to collapse
i give up no voltage anywhere, i think the battery is defective
thanks for you help its going to go in scrap heap- only useful debug feature it does is flash the orange light the odd time when connected to charger- prob means something to barnes and noble
im sorry i purchased this
Aw, don't give up so easily.
I hate an unsolved mystery.
You're sure that your voltmeter is working correctly?
You can't measure anything from the V+ test point to the SD card metal frame?
There's no way to exchange it with B&N?
If you are really giving up, I'll take a look/keep it/fix it/return it/something.
Send me a PM for details.
I'm actually having the same problem. It started a couple of days ago. I tried using this method (http://forum.xda-developers.com/showthread.php?t=1813384) and I was able to at least boot it. However, after only one day (without using it much) it started failing again and now when I use that trick it lasts a few minutes.
I will try measuring the battery voltage and I wonder if it would be a good idea to try to re-root it. However, I don't know if I should try in case it freezes half way through the flashing and I end up with a nice black brick.
I think this issue is happening quite a lot. I hope we can all work together to find a solution.
--Update--
I checked the voltage on the battery and it shows 40mV. So it's definitely depleted. However, when I do the trick and manage to boot the device, it says that the battery is 100% charged and the green LED is on. Conclusion, the device is preventing the battery from getting charged :/ Any ideas how to fix this? Is there any other way I can charge the battery?
40 mV?
If your voltmeter is working and on the correct place, then your battery is way dead, as in broken.
We can argue about whether you should discharge Li ion to 3.5 V, 3.3 V, 3.0 or even 2.5V,
but if any time it's reading a lot less than that, then you have a deceased battery.
If it's open or high resistance, a charging circuit can take it up to 4.1 V easily.
It would show as 100% charged but have no actual charge to backup that statistic.
It's interesting, because the BQ24072 should be able to power up the Nook without a battery.
I think it's that pesky MSP430F2272 that is not allowing the Nook to go on without a battery.
This calls for more experimenting!
Renate NST said:
40 mV?
If your voltmeter is working and on the correct place, then your battery is way dead, as in broken.
We can argue about whether you should discharge Li ion to 3.5 V, 3.3 V, 3.0 or even 2.5V,
but if any time it's reading a lot less than that, then you have a deceased battery.
If it's open or high resistance, a charging circuit can take it up to 4.1 V easily.
It would show as 100% charged but have no actual charge to backup that statistic.
Click to expand...
Click to collapse
First of all thank you for your help.
Maybe I measured it wrong?... I was checking the voltage between the red cable (or so I think) and the metallic frame where you put the micro SD card. I also checked it from there to the black cable and it said 0 V, as I was expecting.
Renate NST said:
It's interesting, because the BQ24072 should be able to power up the Nook without a battery.
I think it's that pesky MSP430F2272 that is not allowing the Nook to go on without a battery.
This calls for more experimenting!
Click to expand...
Click to collapse
Definitely! I'm up for it!
Look, Ma, no battery!
The Nook seems pretty idiosyncratic how it will turn on.
I was trying to make it work just USB powered.
At the least, that gives the people with battery problems a reference point.
On the photo above there are two points labelled "V+ Battery.
Solder the cathode (the stripey end) of a 1N4001 (or better) diode to one of these points.
Connect the anode of the diode to the red wire of a spare, gutted USB cable.
Connect the black wire of the USB cable to the gold border on the circuit board.
Plug in the USB cable. The Nook should boot.
I've tried just stealing the 5V off the Nook's USB connector, but the Nook refuses to boot when both the USB and battery come up at the same time.
The ID and the thermistor circuits don't seem to be that necessary.
i have same DOA device (Simple Touch with Glowlight) , wont power on , green led on usb charger or pc usb cable , quickly reappeared 3630 omap device in device manager when pressed power button
i disassembled device - accu show 2.4v , i recharged accu in turnigy charger - it normally charged about 3 hours and show capacity 1550mah but when i connected it back to the nook it wont power up again and same green light on charger and usb cable , i try all reset combinations - no luck
It is possible for your battery to accept current, charge and still not be able to supply any current.
This would be the case if the charge circuit is working but the discharge circuit is open.
Did you measure the battery voltage after charging?
Can you measure it with some sort of load on it?
50 to 100 ohms would be fine.
If anybody has gotten far enough to tear a battery down any identifying photos of the battery protection module would be appreciated.
i find another working nook (without glow) , tomorrow i check battery (but battery is ok - i try it in charger . internal resistance is low an discharge on 1A corrent is ok )
but now i solder wires from regulated power supply to battery tp - i find nook consumption is 160 mA current on 4.2 v supply and it reacted on power button - if i press pw about 20 - 30 sec is 0 ma current press again and 160 mA still here
battery is ok . screen is ok , mainboard is not ok
working nook eat 150 mA current on start , working nook not start when regulated power supply connected on battery tp - press power button , 150 mA . depress button - 0mA
replaced mainboard ( from nook gl with broken screen) - all working ok
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.
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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.
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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.
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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.
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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.
Does it damage the Board or not?
I accidentally did connect 5v for a second or so,
it did power on, i disconnected immediately, and after that it didnt power on for several hours,
but not sure if it was because of the interruption during boot, or overvoltage.
Can somebody confirm?
(i cant use a diode for voltage reduction, its a bit complicated, i use a load sharing capable solar charger board etc)
its a nook simple touch
Yow, don't do that!
Ok, it should be able to take it, but still.
I've often fed 4V to devices which had their battery blow up.
In worst cases I've used a diode for drop, but the voltage can be pretty variable over load.
The uboot on most things will not continue if there is zero voltage on the battery.
Also, the peak current of a device can go up to 600 mA or more at times.
That kind of current often can't come in through the USB connector.
Finally, battery packs have ID connections and thermistor.
Entirely disconnecting a battery pack will often prevent booting even when voltage is present.
If you have a dead battery pack always keep the the connector, cable and tiny PCB inside.
Attach a power supply to where the naked cells used to connect to the PCB.
For wiring of the battery pack see: https://forum.xda-developers.com/showpost.php?p=42552349&postcount=5
thanks, 2 weeks ago i prepared to measure possible resistors but did a google search before, found your description...
i use the protection board with a 18650 3000mAh lithium manganese (to prevent blow (up)) etc cell and charge it externally,
which requires switching between charging the batt + powering the nook over the batt terminals,
and using the batt for powering the nook , all that while the usb keyboard is connected and in use,
this is done via relay and a really big capacitor, which works great but is a bit ghettostyle.
i tried to use another charger board with load sharing circuitry instead,
but the only easy available module requires 5v minimum input, passes this 5v to load if the ac adapter is plugged in,
if not, it passes the battery voltage to load,
so a diode(+ parallel resistor to maintain voltage drop) or LDO doesnt work because it would at least steal around 0,5 v,
which is to much reduction for the battery voltage, because the nst powers off at ~ 3,7v,
easiest would be to just let the 5v to the nook but seems no good idea.
anyways, it works with the relay