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

thanks for the replies, my phone is out of warranty and before i found this forum i repaired it myself with a filed down tip and i also scratched the sides away to add more solder which has lasted great until i ran into the charger cable trying to catch my son toddling near the stairs. Hitting the cable so hard ripped all the pads off. iam not going to attemp it myself im taking my phone and mipo's pics to a friend who has the tools and is more than skilled to do the repair.

Thanks again il take some before and after pics if its successful as u will see the mess that is left after my first repair

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

Is this true? Has anyone had any success getting this done?

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

It is most certainly true as many have been able to get replacements.

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

Do you have the circuit diagram?

http://rapidshare.com/#!download|359...atics.pdf|6623

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

Not yet i did google something but forgot to save it , i would appreciate a link if you have it thanks.

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

Sorry i forgot to put the link in, done it now look at my last post.
Unless your registered you will have to go for the slow download but it is not that slow.

I wish you luck and if you run into any problems just get on here as i should be here to help.

Done loads now and shame on me for not doing a dummies guide but i will do soon because Texrat will only nag me to death if i don't lol.

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

Soldering tips.... i use a weller soldering station with a very fine long pointed tip and i always put the board into a jig, is best to use anti-static precautions (wrist band) and make sure the tip is hot enough but not full on as you will burn the board and melt the pins into the jacket they are encapsulated into, take care here ok.

Scrape away the paint on the earth plain either side of where the usb port was and if you look carefully you will see the pads that the port was soldered on to is so small there is a gap between the pad and the main earthplain, dont worry about this just make sure you scrape enough paint off and apply enough solder to either side, that will make sure it never lifts off the board again.

Do the pins last (on the rear of the port) making sure you have got the usb port lined up correctly with the hole on the case before soldering the pins.

I use a bench magnifier with internal light to work through.

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

Here is the service manual for the N900, it will show you how to take it apart and put it back together etc etc.

http://rapidshare.com/#!download|376...l_1_2.pdf|1868

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

the difference between : first link is AB type like N8 ( wrong picture ) and second is B type as original n900
you have the chance to mod your n900 receptacle to be host mode compliant :) (filing cabinet is needed in that case )

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

I've got mine here, world wide shipping, no shipping charge:
http://cgi.ebay.de/Buchse-Nokia-6500...item43a4ee5d86
You'll also find other auctions with the same connector.
The listed Nokia models got the same connector.

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

Hi Mipo,
how did you get of that metal shield over the parts? That's exactly where I have to solder, if I remember right.

At the moment my N900 is build together and in use. Battery is charged by wires directly at the battery (at the open backside), with a laboratory mains supply. Really not too comfortable... :rolleyes:
(and you have to know how li-ion batteries are charged!)

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

http://i51.tinypic.com/5np368.jpg
You're talking about the EMF shielf over the components? From the first looks I've taken at the board, it looks to be soldered on one or both sides, and if Mipo can confirm this, it looks like he had to desolder it before working on the USB port.

I just purchased an n900 off ebay with a broken USB connector, and I've picked up a MOLEX - 47346-0001 off digikey. Im pretty sure it can be drag soldered without removing the metal EMF shield off the other components if you have a sufficiently thin soldering iron. I'll post a quick update when I get a chance to confirm my idea.

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

can i solder my pc usb port without any experience of soldering?

can you plz suggest me what company of soldering wire should i buy?

and what is the best soldering machine,which volt and more plz???

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

I wouldn't do any soldering without having any experience. these are very small parts and it's not easy. I've failed and I have some experience. at last I didn't damaged anything :).
now I am using my old 5530 as a charger for n900 :D
next time I'll be in Poland i need to contact mipo :)

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

Right, the EMF shield. I was able to remove the cover plate of it but the other part of it is soldered to the board.

I think I'll try to get the EMF shield (maybe partially) off with desoldering braid.
good luck for your try! I'm awaiting updates :)

edit: Maybe I'm giving it up. I got a part of the EMF shield removed, by simply cutting it of with a small scissor and soldered cables to the usb socket. But soldering wires directly to the parts seems impossible for me, the just fall off again..

edit2: got it working I guess, then I had to solder again, because the socket was mounted too high on the board, then I made a shortcut by getting lead on the contacts.. :(
charging again with my 2 wires on the battery. maybe next try another day..

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

Anyone done a mod to expose the 5V and gnd as large pads on the outside, since it seems the usb connector is so prone to wear & tear?
Or is it possible to get at the charger through another way than usb?

I bought a nintendo 3ds recently, and I'd almost forgotten how practical those 80s and 90s "charge stations" were.
It'd be nice to build a ZIF charge station for n900 with spring loaded connectors.

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

Dude, I have the same problem. And guess what? I live in New York City, my phone has been sitting in the Nokia care center for three months now, and the people there are saying they don't know what to do to fix it. And oh yeah they charged me a sweet 120$ before even starting. I realized my mistake, i should have just asked the forum.

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

IMHO not at the charger but at the battery, that's how I'm charging since then (image attached) but don't go over 4.2 volts at the battery, or it will explode!

I ordered a second battery and a charge station, costs something around 5€.
A charge station for the whole device would be cool, but my wish is still to have full USB connection, for charging, flashing new firmware, flashing other OSes..

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

of course you could mount pads (connected to the battery inside) somewhere outside of the device, even if it'd be hard not to look like a dirty hack :) and charge it with a charger like this. IMO the charger doesn't care if the battery is connected to the device.

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

Just a quick note, most lithium ion chargers are pretty standard. I don't have a nokia charger but I use one for my camera (FUJI) and just manually wire the leads to the batteries I'm using. Make sure you get + and - right, and the third temp sensor (or for more proprietary batteries, communications) lead hook it up appropriately. The nokias seem to only use it as an analog temp reading, and the charger terminates properly @ 4.2V on its own.

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+.

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

You just reminded me. Used to use that stuff too when repairing broken tracks and worn contact pads in quartz watches.

Like the humor that's been interjected into that guide though. ;)

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

First, excuse me if this is considered crossposting.
Though, I discovered that you can use the pads beneath the battery to actually gain access to the USB and charge your device.
I describe this in more detail here:
http://talk.maemo.org/showthread.php...818#post997818

I just mention it here as it may be of interest for you as well.
I didn't post it here as this thread is about fixing/re-attaching the existing USB to the mainboard instead of using an alternative method.
So imho all stuff about creating an alternative way for charging or getting access to the USB should go into the other thread linked above.

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

are there fuses for the 5v wire?? i tried to fix my n900 by myself an had everything soldered together but usb was not regognised.... BUT

when i use a cutoff usb cable and short the Data wires it boots when i put in a battery ... that means the data pins are correct soldered ...

but i have connection with gnd and +5v (from cut off usb cable to testpoints on the pcb) too.

that means:

the usb is soldered it correctly.

data wires are regognised

issue could be an fuse...

i never saw an fused gnd

so it must be a fuse somewhere on +5v...
or an broken USB cotroller.

someone know where the fuses are??
how can i test the usb controller??

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

there is a fuse on USB VBus 5V, directly after the microUSB socket. That part is called "F5300". You'll find it in the "N900 RX-51 Full Schematics", page "GAIA_05" and "Rover_Component_Finder" pdf.

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.

A fuse can be shorted, when you know what you do after that! I broke a fuse in my old N810, when I inverted 5V and GND accidently..

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

The pictures from http://talk.maemo.org/showpost.php?p...3&postcount=12 that a lot of people seem to refer to are no longer available. If primo still watches the thread, could you put them back up or has anyone else similar pictures?

Thanks

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

Sorry. I did a cleanup on the server and noticed that I removed too much. Pictures came back:)

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

oMFG my usb broke again :( F***********

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

Just wondering, did you file down the microUSB connectors on your data cable and charger?

PS: I'm a fellow Hamiltonian BTW! I'm travelling in Asia for the next few months.

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

I tried to soldering it back on but my soldering is too big to fit in the small space. I can only mount the ground.I'm guessing sending it again for repair.

Fuc* put it back in and my screen gone funny turned it off and turned it back on it back to normal again.. Pewff

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

Good news guys. I have successfully reattached the MicroUBS back onto N900 board with a soldering iron.

It's charging and accepting data transfer. :)
Cost $59.95 for a soldering iron and hours of works. lol.
Photos are up soon.