Re: Soldering advice needed for re-attaching N900 USB to mainboard.
 

Please note that the Nokia chargers are NOT chargers. They are power supplies. The real charger is inside the phone. Therefore connecting the "nokia charger" to the battery is a bad idea and potentially dangerous, since you're feeding it 5V without a proper charging circuit.

Re: Soldering advice needed for re-attaching N900 USB to mainboard.
 

When my usb connector broke off, it also ripped off the two DATA1 and DATA2 pads.

But I'm having a hard time soldering onto those points (marked in blue).
They're almost gone now :(

http://tabon.ath.cx/~mastag/pic1.jpg

I do have the right equipment, kynar wire, flux and a very small 0.5mm tip.
However those point are almost burned away, I can't even see them anymore.
When my phone fails I won't be able to flash it anymore without a working usb connection.

Aren't there any alternate points for data1 and data2?

Re: Soldering advice needed for re-attaching N900 USB to mainboard.
 

I have had mine repaired (re-attached) two times now in Lagos, Nigeria. Works great, took less than two hours and cost me less than a hundred bucks each time. These guys can fix just about anything :D.

I guess there is one upside to working in Nigeria at least. :p

Re: Soldering advice needed for re-attaching N900 USB to mainboard.
 

Looks like you're burning them away with the soldering iron, with each attempt.

If you're super-careful and you have a mega-steady hand, http://www.kemtron.co.uk/e-shop/cond...-adhesive.html. I used to use it for repairing quartz watches when I was working as a watchmaker/repairer.
Saves any further heat damage.

Re: Soldering advice needed for re-attaching N900 USB to mainboard.
 

Like this idea and will be the only option not to use soldering equipment especially for those unable to solder onto tiny pads or attatch link wire even a more of a nightmare.

It is however possible to scrape away the paint and bare tracks to enable link wire to be soldered along a bare track when both track and wire have been tinned first before attempting to attach the link wire to the track, try not to solder directly onto a surface mounted component unless your iron has a very sharp tip and are quick about it.

Re: Soldering advice needed for re-attaching N900 USB to mainboard.
 

That's my problem, too. Filesystem errors on root, some apps don't work anymore, can't open the contact list. I have to reflash!

There are debug ports, also for USB. But I couldn't get a working connection with them, yet. I tried with Data+, Data- and GND.
I'm not assured this is really USB. Maybe I'll have a look at the schematics/PCB

edit: I've found J5300 and J5301 in the schematic and the PCB, these are described as USB D+ and D- in the schematic.

Seems like another way for a USB connection, without soldering on components again :)

Re: Soldering advice needed for re-attaching N900 USB to mainboard.
 

I think you could be onto something with those 2 pads. If you look under your battery they are accessible through a hole in the shielding, as are the 7 & 5 pin pads. I'm thinking they are there to be used by a service centre for the purpose of flashing etc.

A quick search for "Nokia N900 flashing cable" got this http://ditsonline.com/3385-nokia-n90...ufs-7-pin.html. If you look at the full size image you can see there's 7 spring loaded pins on the box. This thing fits inside the battery compartment and the pins contact one of the sets of pads.
There's gotta be something out there that makes use of those two USB pads.

Re: Soldering advice needed for re-attaching N900 USB to mainboard.
 

yes, USB and flashing. I tried to connect them to my computer with the device switched on, the device was never recognized. I give up with these and will try again with wires and a micro-usb socket, later.
Maybe someone who has his device opened, could check if these two (supposed to be) USB pads are really connected to the USB port?

the flashing cable looks interesting and cheap, but you also need a special USB key to connect it to the computer, which is not that cheap, like 30€ or something and who knows what software is needed..

Re: Soldering advice needed for re-attaching N900 USB to mainboard.
 

If you guys are going to try soldering, I'd really recommend using Kapton tape. It's a high temperature resistant tape that can prevent you from damaging any of the adjacent components inadvertently. Btw, an SMD soldering guide with Kapton tape: http://ultrakeet.com.au/index.php?id...=kaptonMasking

Have you guys had any luck with using the tabs? If you are going to try and flash it using the extra pads, make sure you connect the GND (ground) pads as well. The VCC (5v) might be optional, but I'd rig everything in properly.

Re: Soldering advice needed for re-attaching N900 USB to mainboard.
 

Note that these are on the other side of the ESD circuit, and after the isolator. If you have any kind of static on the line it's going to transfer directly into the controlling chip. It may be best to attempt to emulate the ESD circuit (or at least put an isolation circuit in place) to prevent that.

I also noted that the schematic is showing the ID line is connected, something the h.e.n. crew said was not the case last I recall? Or maybe it's connected in a way that we can't read it? Hmmm... In any case, the one toward the battery should be D+.