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Hi guys,
i have a SGH-i780 Smartphone and i am quite happy with it. The only negative aspect is short battery lifetime when beeing always online for push-mail.
Therefore i would like to have a docking station for my device, where i place it and it is been charged. But as the f******g Samsung developers placed the charge/sync connector on the upper right side of the device i would always have to place it in docking and connect charge cable.
Therefore i thought about modifying the phone which means making the 3 battery connectors accessbile from outside to connect the external charger box (including charging electronic!).
And here is my question: do you think connecting a charging electronic directly to the battery while it is inside the phone will harm or destroy parts of the phone? I am wondering whether the internal charging circuit inside the phone will get hurt by connecting another circuit in parallel ...
Thanks for your comments!
For sure this could hurt your device...............
In this case I'd say the risk isn't worth the reward. The risk is that you fry your phone, and at worst it sparks and causes other damage. You can have it check for mail less often, unless you need your email to be live.
such heavy modifications never go without harm to technology.
It simply is not designed to work that way, so you'd be better off with a docking station or a better Powerpack.
You can find those on Ebay for pretty low prices...
thanks for your replies!
I also thought about wiring the +5V and GND pins from the USB connector to the bottom of the device and connect a power supply directly (which but be the way it is thought to be) but the usb connector is very very tiny and i doubt i will be able to connect and solder the cables to the right pins ...
any furhter ideas?
not really no... trying such delicate soldering quests is generally not a good idea without the proper Equipment.
Whatever you do to modify your phone, it will void your warranty and you'll not get a replacement device if you trash yours...
Don't do this!
By bypassing the phone's own charging circuit you are removing any sort of overvolt protection!
Although I am not familiar with this phone and your post is somewhat hard to understand, I take you usually sync it, then take the battery out to charge that separately with another cable?
If that is the case then, no, don't move the connector so you can charge directly to the battery! It will be potentially very bad for the battery and phone.
Out of the question
DO NOT under any circumstances play with your battery.
What you were taught in your physics class do not apply to microelectronics!
There are many 5V+ out there and ALL are different!
While rms value is the same, the waveforms of the current/voltage can be any imagineable. So, the best thing to do near your cradle is to pin a sign "KEEP OUT!"
Technically, you could create another charger that connects directly to the battery. There are dozens of ways.
BUT, since you asked, then you don't understand how. Assuming it is a liPo or LiIon battery, if you charge it wrong, the resulting explosion and fire will be nasty.
Why not get a second battery in an external charger, and just swap them.
worwig said:
Technically, you could create another charger that connects directly to the battery. There are dozens of ways.
Click to expand...
Click to collapse
Do you mean while it's inside the phone?
worwig said:
BUT, since you asked, then you don't understand how. Assuming it is a liPo or LiIon battery, if you charge it wrong, the resulting explosion and fire will be nasty.
Click to expand...
Click to collapse
I already have another appropriate charger because Samsung ships this phone with an charging box.
worwig said:
Why not get a second battery in an external charger, and just swap them.
Click to expand...
Click to collapse
Because then i would always have to take a second battery with me, every time! That's awful!
I just want to have a docking station, that charges the phone while it's plugged in ... without terrible wiring needed. Then i can make sure the phone is always fully charged when taking it.
I attached 2 pictures showing you my 2 ideas:
1) wiring the external charger directly to the battery (but of course this would also mean connecting it directly to the internal charging circuit of the phone!). I fear this would damage the phone!
2) wiring the power supply to the power supply connector. This should definitely work, but soldering the cables on the tiny connector will be a pain!
Thanks for your help!
ok here's what I want to do.
Permanently integrate a nexus 7 in my car dashboard in the double din radio opening
Remove the battery from the nexus 7 and hardwire to always on power from the car battery
Hardwire the power button to a button installed in the dash
Dashmount a usb port connected via otg for hotswapping media
Hardwire a potentiometer into the dash for volume control
all of the above is fairly simple except for power supply, otg+charging is a possible solution but a car battery wired solution is far better so what i need is information on what the battery pins supply in terms voltage/amperage so i can create a 12v to direct power converter or a device that already does this. any help is appreciated TIA
bump, if someone knows i could really use this info
b22ri22an said:
ok here's what I want to do.
Permanently integrate a nexus 7 in my car dashboard in the double din radio opening
Remove the battery from the nexus 7 and hardwire to always on power from the car battery
Hardwire the power button to a button installed in the dash
Dashmount a usb port connected via otg for hotswapping media
Hardwire a potentiometer into the dash for volume control
all of the above is fairly simple except for power supply, otg+charging is a possible solution but a car battery wired solution is far better so what i need is information on what the battery pins supply in terms voltage/amperage so i can create a 12v to direct power converter or a device that already does this. any help is appreciated TIA
Click to expand...
Click to collapse
Can't you just use the USB port to charge it? it takes 5V, and 2A. With a car battery it should have enough amps, the voltage is what you'd need to regulate.
But if you really want to take out the battery instead...can't you just use a volt meter to see what the N7 draws from the battery? I'd guess it's 3.7v lithium ion but I'm not positive. I couldn't find the specs on google either..
As far as I have read there are some major difficulties getting otg+charging to work at the same time and I need the storage space provided by external storage. Having the car power source replacing the nexus 7 battery would eliminate that problem altogether.
I was hoping that someone here had known the voltages since I don't currently own or have access to a multimeter to test for myself. Knowing the voltages in advance would give me the opportunity to see what would be entailed financially to build the project and determine if its its financially acceptable to me, if the project isn't viable the money spent on the multimeter to do the tests would be wasted as it's not something I need for anything other than this particular project. So in the interest of trying to save $20 I figured I would ask here first and that there was a good chance that someone might have the information I needed.
b22ri22an said:
As far as I have read there are some major difficulties getting otg+charging to work at the same time and I need the storage space provided by external storage. Having the car power source replacing the nexus 7 battery would eliminate that problem altogether.
I was hoping that someone here had known the voltages since I don't currently own or have access to a multimeter to test for myself. Knowing the voltages in advance would give me the opportunity to see what would be entailed financially to build the project and determine if its its financially acceptable to me, if the project isn't viable the money spent on the multimeter to do the tests would be wasted as it's not something I need for anything other than this particular project. So in the interest of trying to save $20 I figured I would ask here first and that there was a good chance that someone might have the information I needed.
Click to expand...
Click to collapse
oh ok..well have you taken a look at the battery? It should just be 3.7v, I don't think it would be too hard to find which pins it is. Maybe take a LED and test it across the pins?
Also, I have heard reports OTG + charging is working fine on CM10 with a patched kernel. you might want to check this thread: http://forum.xda-developers.com/showthread.php?t=1934722
mvmacd said:
oh ok..well have you taken a look at the battery? It should just be 3.7v, I don't think it would be too hard to find which pins it is. Maybe take a LED and test it across the pins?
Also, I have heard reports OTG + charging is working fine on CM10 with a patched kernel. you might want to check this thread: http://forum.xda-developers.com/showthread.php?t=1934722
Click to expand...
Click to collapse
I've been participating heavily in the arena of OTG + charging simultaneously, as well as using USB audio.
To answer the OP's question directly: I have demonstrated (to myself) that I can power down my Nexus 7, disconnect the battery connector, plug in my y-splitting OTG cable with power in one plug, and an unpowered USB hub in the other plug. [Plugged into the USB hub is a flash drive, USB DAC, and I'm sure a keyboard would also be an option.] Then I turn on my Nexus 7, and in the OS it shows the battery at 0%, but charging (obviously it's not actually charging without the battery present...).
I even booted up the Nexus 7 normally, with all the same stuff connected to USB, and then disconnected the battery connector... and the Nexus 7 remained on!
I've thought about integrating some sort of tactile switch that essentially disconnects the battery whenever the switch is depressed. So then part of the car mount could be a little protrusion that presses this switch whenever the tablet is inserted into the car mount. That way whenever the tablet is removed from the car mount, the battery will take over without removing power from the motherboard.
MetalMan2 said:
I've been participating heavily in the arena of OTG + charging simultaneously, as well as using USB audio.
To answer the OP's question directly: I have demonstrated (to myself) that I can power down my Nexus 7, disconnect the battery connector, plug in my y-splitting OTG cable with power in one plug, and an unpowered USB hub in the other plug. [Plugged into the USB hub is a flash drive, USB DAC, and I'm sure a keyboard would also be an option.] Then I turn on my Nexus 7, and in the OS it shows the battery at 0%, but charging (obviously it's not actually charging without the battery present...).
I even booted up the Nexus 7 normally, with all the same stuff connected to USB, and then disconnected the battery connector... and the Nexus 7 remained on!
I've thought about integrating some sort of tactile switch that essentially disconnects the battery whenever the switch is depressed. So then part of the car mount could be a little protrusion that presses this switch whenever the tablet is inserted into the car mount. That way whenever the tablet is removed from the car mount, the battery will take over without removing power from the motherboard.
Click to expand...
Click to collapse
Lol, yes, I think I had you in mind when I said that.. I'm still waiting for my Y cable. I won't get it till at least 1.5 weeks..
MetalMan2 said:
I've been participating heavily in the arena of OTG + charging simultaneously, as well as using USB audio.
To answer the OP's question directly: I have demonstrated (to myself) that I can power down my Nexus 7, disconnect the battery connector, plug in my y-splitting OTG cable with power in one plug, and an unpowered USB hub in the other plug. [Plugged into the USB hub is a flash drive, USB DAC, and I'm sure a keyboard would also be an option.] Then I turn on my Nexus 7, and in the OS it shows the battery at 0%, but charging (obviously it's not actually charging without the battery present...).
I even booted up the Nexus 7 normally, with all the same stuff connected to USB, and then disconnected the battery connector... and the Nexus 7 remained on!
I've thought about integrating some sort of tactile switch that essentially disconnects the battery whenever the switch is depressed. So then part of the car mount could be a little protrusion that presses this switch whenever the tablet is inserted into the car mount. That way whenever the tablet is removed from the car mount, the battery will take over without removing power from the motherboard.
Click to expand...
Click to collapse
Am i understanding you correctly? If i unplug the battery, and just have the OTG cable plug into the charger, it would be able to power on and off and run just fine?
ho9984 said:
Am i understanding you correctly? If i unplug the battery, and just have the OTG cable plug into the charger, it would be able to power on and off and run just fine?
Click to expand...
Click to collapse
This was how it worked while the N7 was running Jelly Bean 4.1.2. I can't guarantee it would operate the same on 4.2.2.
MetalMan2 said:
This was how it worked while the N7 was running Jelly Bean 4.1.2. I can't guarantee it would operate the same on 4.2.2.
Click to expand...
Click to collapse
Someone tried it on Reddit. Removed the battery and tried powering it on with only OEM charger. The screen just flickered. They were on 4.2.2
I am curious about removing the battery and hardwiring as well as I am gathering parts to put my Nexus 7 in my car dash. The problem w/ the OTG route - it gets pretty hot down here and I'm afraid the battery will have some long term issues (ie...could leak/explode). So, hardwiring it would be preferred.
Any ideas for hardwiring?
with the new nexus 7 coming out I am just going to mount the wireless charger behind the tablet dock, now I just hope otg is supported with the slimport on the new nexus 7
I bought a Nexus One with the infamous broken power button issue, and I am curious what would the effect be if I short the VCC and GND line in the charging port? Has anyone tried that? I am thinking that it will either fry the board or trick the phone to think that it is charging.
The reason I want to do this is because I travel a lot and I might not have access to USB charging if I want to swap the SIM card. I am familiar with the other tricks regarding remapping the trackball_center and I am going to install a version of CWM that doesn't support charging (that way the phone boots when I plug a charging cable).
So long story short... what do you think about attempting to short the micro USB charging/data port?
dcalpha said:
what do you think about attempting to short the micro USB charging/data port?
Click to expand...
Click to collapse
Not much.
Unless the unit is in USB host mode there will be no voltage on the Vcc line.
Even in USB host mode it should be current limited and do no damage.
Still, I wouldn't do it.
I don't know why you think that shorting it will do something useful.
Renate NST said:
Not much.
Unless the unit is in USB host mode there will be no voltage on the Vcc line.
Even in USB host mode it should be current limited and do no damage.
Still, I wouldn't do it.
I don't know why you think that shorting it will do something useful.
Click to expand...
Click to collapse
I actually do not know, thus I asked... just trying to think outside the box about a way to trick the phone to think it is charging short of carrying a portable battery charger with me (which can be problematic on carry-on luggage).
Another idea I am thinking about is building a small flex cable using a conductive ink pen that permanently connect to the phone's battery on one side and a cut down male micro-usb on the other side (to slim it down). Such cable would be small enough to fold under the battery cover and allow it to close.
My question is: Will the ~3.7v be enough to get the phone to start charging? and do you foresee any issues with feeding power from the battery right back into the phone's charge port?
dcalpha said:
Another idea I am thinking about is building a small flex cable using a conductive ink pen that permanently connect to the phone's battery on one side and a cut down male micro-usb on the other side (to slim it down). Such cable would be small enough to fold under the battery cover and allow it to close.
My question is: Will the ~3.7v be enough to get the phone to start charging? and do you foresee any issues with feeding power from the battery right back into the phone's charge port?
Click to expand...
Click to collapse
I think 3.7 won't be enough. Coz usb giving ~5V. So phone won't charge at smaller voltage.
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 ?
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?
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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.
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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.