Originally Posted by Estel

@gebeleysis
to be honest I have no idea - my gas-powered soldering iron is no name It's much more important to use thin tip - as for "heating base", everything that doesn't blow gas container into Your face is ok.

As for tips, I also can't be much of a help, as I've done them myself - using cooper, most of the times. unfortunately, it may be quite hard to create soldering tips on Your own, if You don't have appropriate tools.

In such case, You should determine type of soldering iron You want to buy, by it's extensibility and availability of replacement tips and their types.

Anyway, here is photo of my soldering tips collection + soldering iron, for reference:

/Estel

Originally Posted by lazart

4. sounds good I spent many hours trying to repair the usb socket. The only thing I got to work was temporary connect an usb cable directly to the pads, because I had to do a reflash. IMHO repairing the micro usb socket only makes sense if you still have the intact pads on your board.
After my first n900, which I failed to repair (I used a wall wart charger + second battery for a long time), didn't boot anymore, I bought a "new" one with a broken display from an online auction. Because the display from my first one was OK, I replaced it with the broken display from the second one. And there I was: A full functional N900!!
I also hoped to swap the internal memory, but failed, it's soldered on pads _under_ the chip.. whatever.

and it's worth to make backups with the backup function of the device on a small microsd card..

good luck!

Originally Posted by jabawok

I managed to repair my faulty USB port today. Many thanks to everyone to posted pictures to this thread, it was of immense help.

I apologize for lack of photos; I found myself reaching for my N900 several times to take some shots, then realised it was in bits in front of me :P

My port was still attached, but had dry solder joins on one or more of the 5 pins connecting to the pcb. (this means the solder has snapped and the legs are not bonded to the board, they are just touching it [occasionally, in my case].)

This symptoms of this are:
- Phone charges but only if you turn it upside down
- Phone charges but only if you fiddle with the usb cable till it's "just right"
-Phone charges when you hold the usb connector in the socket (and possibly gently push)

I found it got progressively worse to the point that I would spend 5 minutes every night making small adjustments to the cord and phone until it would start charging.

I pulled the device apart according to Nokia_N900_RX-51_Service_Manual_Service_Level_1_2.pdf (google for it).

I stuck a small piece of paper over the camera lense to prevent dust getting in, and removed the RF shield from the chip immediately next to the usb connector. The little clips on the side just click off with a small flat blade screwdriver. I then got some small side cutters and cut a very small section out of the RF shield rail (what the RF shield clicks down on) to gain access to the back of the USB connector. This should expose the surface mount solder points.

I then wound a pin around the end of my soldering iron, tinned it on and chopped the end off the pin off (it was too fine). From there I managed to heat up each contact till the solder re-flowed (I didnt apply new solder at all). Its very difficult to see exactly what you are doing with bare eyes - you cant tell if the solder has remelted. I experimenting with various lengths of time holding the tip onto the joins. Between each attempt I connected the screen and held a battery on the back of the board, to fire the device up and test for any improvement to the usb connector. I found that the best approach is applying the tip from a 45 degree angle, to clear the RF shield bracket and have a degree of visibility to the pins.

Once I had it reliably charging, I scraped away 1mm of green enamel on either side of the connector where the sides are soldered down, and applied a nice amount of solder to each side to lock it into position forever. Its imporant to not heat the connector up too much else the internal plastic parts will melt, but enough so that the solder "flows" onto the connector and onto he board where the enamel has been scraped off. Also take note of where the board fits into the plastic shell, there is a screw right next to one side of it; too much solder on the board will mean the board wont sit correctly on that mountpoint.

Hope this helps someone.. attached are some shots of my makeshift SMD soldering iron mod.

Originally Posted by gebeleysis

TheJason,
Quick advice: use a powerful enough soldering iron (this was my first mistake) because a weak iron will just have all it's heat sucked out without being able to melt the solder on the joints.
Another advice: you will have to cut part of the shielding away. If you use a tip that's thin enough to fit between the port and the shielding it will probably be to thin to properly heat the joints anyway - not enough heat transfer.

Estel, Lazart and others who've successfully done this. I need help. Re-soldered the port today, but it acts wierd.
Symptoms:
- when plugged into the PC the screen lights up, but the mass storage vs pc suite mode dialog doesn't come up.
- when plugging a wall charger in - it starts charging but disconnects by itself in 1-2 minutes. Then, without any interference, starts charging again, and so on. In about 10-15 minutes it disconnects/reconnects each 2-3 seconds.
- tested the connections with a tester: first plugged a USB cable (for ease of access) and it shows me that the 3 pins that count each connects to only one pin at the other end - no bridging. The two data pins have no contact with the cable shielding (ground) and the +5v has about 10 ohms resistance towards ground. Also there's direct contact between two leftmost pins and base (see picture http://i1032.photobucket.com/albums/...-overview2.jpg).
I'm very frustrated. I'm afraid that some components might have been damaged by heat during the operation. Has anybody encountered this? Any ideas why this might happen?