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Posts: 5 | Thanked: 2 times | Joined on Aug 2012
Originally Posted by Storm_11 View Post
I've read about somebody wanting to try this, or perhaps achieved it, but can't find where.


Using these, the back of the pcb of the n900

Microusb cable:

* 1 - (black) GND / ground
* 2 -
* 3 - (green) Data
* 4 - (white) Data -
* 5 - (red) VDC / plus / 5V
* 6 - shield

Using this data:

Is it possible to create a new Microusb connection? Where my microusb connection was, there are no more metal solder points to be able to repair the microusb port.

Unsure 100% of the following:
Line up TX with Data
Line up RX with Data -
GND with GND

But then where does one obtain the positive voltage (usually 5v). On the cable this is VDC 5v, but the battery positive cannot supply this voltage.VCC according to the link "Common Collector Voltage - main power supply ( usually 5V )". But would this work? the provided link doesnt actually specify where VCC is.

The cable would then be routed to where the microusb was. So I'[d attach a new microusb port, with the cables being soldered from the new microusb port, to the connections above.

edit: I already have a desktop charger. I also use TinySMB to transfer my files to and from pc. The only reason I'd have for doing this is if I want to reflash.
umm.. I'm new here and hav owned 2 n900's but both of dem bricked, av got important files that i want to extract frm dem and i need help from this thread, my microusb is broken and took some of the board wit it. I did a reflash wit cables connected to data data- GND and 5v.. And yea it worked.. But now i stupidly tore out d metal tracks on data data-.. Now, m just wondering if i can get access to d phone by connecting cables to RX/TX, 5V and GND so i can do a reflash, as indicated in d first post on this thread.. Any help will be useful.. Thanks

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Posts: 5 | Thanked: 2 times | Joined on Aug 2012
Hi, u happen to be very helpul in dis thread can u help me out?

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Posts: 3 | Thanked: 1 time | Joined on Jan 2013

I am new here and have registered to ask a question about the test pins.

I charge my battery externally since my usb connector broke. However, today my phone has begun entering a reboot loop after I replaced /usr/bin/camera-ui, and I want to boot into USB mode to disable the watchdog timer.

My question is: would it work to power the phone from the battery, and connect the USB to +D/-D alone? I see no reason why this should not work, but I thought I would ask. I was planning on soldering +D/-D to a pair of wires that can be wrapped around the battery.

I believe this would be easier and relatively safe (since I'm not touching the +5V pins), and easier than repairing my USB connector since I will only be using it once or twice.

Happy new year,

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Posts: 99 | Thanked: 64 times | Joined on Jun 2009 @ Stuttgart/Germany
it's not dangerous to touch the +5V/GND pins, but you can flash the phone battery powered only.
Posts: 3 | Thanked: 1 time | Joined on Jan 2013
I was worried about endangering the phone. It was said here that it is important to connect ground before anything.

When you say it is possible to flash the phone with battery power only, does that mean I can wire the two data pins only and still boot it? I have a battery charged from an external charger.

I must admit that I spent the better part of the night trying to solder just the ground and was not able to do it with such a terrible iron, no flux, and a shaky hand.
Posts: 3 | Thanked: 1 time | Joined on Jan 2013
nm, I see that you already answered the question yourself in this post:

I also want to test USB connectivity, I think also USB power is required. As I mentioned before I couldn't get an USB connection with just the two data pads
Posts: 56 | Thanked: 19 times | Joined on Jan 2013 @ Netherlands, Flevoland

I'm trolling around on this forum for a while now.

I want to do a project to make the N900 charge wireless.
I'v got instructions how to wire it to the battary ( ), but I want to do it straight to the phone...

Can it be done with the pads under the battary, and if yes, should it be the GND and 5v..?
Or should I use some pads at the USB port (don't want to remove that yet..)?

I've got minor experience at soldering and stuf, and maybe got some back-up help.
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Posts: 99 | Thanked: 64 times | Joined on Jun 2009 @ Stuttgart/Germany
Originally Posted by Hansie_k View Post
Can it be done with the pads under the battary, and if yes, should it be the GND and 5v..?
yes, you need GND and 5V pads. But your voltage must be very accurate, 5V +/- 5% or something (see usb specification). Is your kit not for charging a battery directly? With charge control? Then you won't have 5V there.
You should also have a look at the n900 schematics.
Posts: 16 | Thanked: 8 times | Joined on Jun 2012 @ Earth
I know where the D+, D- and GND Contacts are....

Where exactly did you solder the 5V? Which contact did you use? The USB Power Detection or the Battery's one (VBat+)? (According to this picture)

Is it hard for you to post any picture with the Phone dissasembled? To be clear how the wires are soldered?

Thanks in Advance!

Originally Posted by lazart View Post
sorry, that it took so long, I wanted to make pictures before I post. Pictures come later, now some info on my hack, because this is a real cool community which helped me a lot:

I soldered 4 wires on the pads (D+, D-, GND and 5V), about 5 till 10 cm long, on the pads of the N900. The device has to be disassembled for that, I couldn't solder on the pads as it was assembled (maybe with a very small oldering iron it could be possible).
I put the wires through the holes by that you could usually access the pads if the device is put together (and we need it to be together.. )
As mentioned there was no working connection without the battery, so I had to put the battery back in with the wires going by it. That's why you have to use really thin wires.
After putting the device halfway together, at least the battery must have a connection, I connected an USB cable, which I cut on one side, that it has just the plug for the computer and wires on the other side, that where temporarily connected to the wires on my phone. Now my PC recognized a new USB device, rest is flashing, see in the wiki.
Those wires are still on my phone, I'll keep them until I have a USB socket mounted again.
The back cover still fits, a bit harder than usual and I open it regulary if I swap the battery, charged at a wall wart charger.

Mind that 5V and GND or any connectors of the battery should never be shorted!
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Posts: 5,029 | Thanked: 8,596 times | Joined on Mar 2011
first page of this thread:

Previous page:

No problem

N900's aluminum backcover / body replacement
N900's HDMI-Out
Camera cover MOD
Measure battery's real capacity on-device
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test points, usb port

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