In the first picture it looks like you filed down the PCB a bit. what is the grey material you uncovered? Please tell me it's aluminium, because then your fix may actually work better than mine.

SnPb solder alloy ( 63%-37%) melting point 183 oC
I filled around usb green solder mask to uncover copper layer and solder a little bit more

Yes, that is pretty much the solder I have as well.

But I was referring to the silver line that you created by filing down the green layer off the PCB. Is that entire line aluminum or copper? Or is that just the PCB material with the green paint removed?

I'm really tempted to resolder my N900 as well, but only if there's something more to solder to. If the only metal within the PCB is contained within the pads themselves, they'll just break off along with the extra solder.

That's why I didn't even try it in the first place, evne though I'd rather solder 10 things than epoxy one.

Edit: Oh, and I take exception to your calling my epoxy job a placebo. Seriously, from what I could tell, that upper PCB is sandwiched between the main PCB (system board) and the plastic casing of the phone. It's as solid as it'll get, as it's held tight by the LCD screws.

Great thread thanx for sharring !

I guess repairing a detached usb port is not impossible once the case open ...

what silver line ? i don't understand . edit the picture and mark it.
around pads is copper ground plane and pads are separated from this layer because this layer dissipate heat in solder process and final solder can become "cold" . in all designs ground pads obey this rule

http://www.pixhost.org/show/668/1649..._0366_edit.jpg

I used my Jedi Paint skills to highlight the area. What is that gray stuff? I keep asking these questions because I never filed down a PCB before, and I don't know how many layers there are.

Next time first search forum for link to service manual L1/L2 which has step-by-step instructions for disassembly and assembly.

this is copper ground plane exposed . this layer is painted with green solder mask ( i don't remember english industry term )
I scratched this layer until i reach copper layer to solder on it . n900 pcb is multilayer and signal traces are in the middle . exterior copper layers are mainly ground plane.
i think you don't deal with pcb

Hmmm,

That might be a better solution than epoxy - expose the ground layer next to the UCB plug and run a bead of solder onto it and then the plug.

Or alternatively if you still want to do the epoxy it would not hurt to take a nice sharp knife and scratch the ground plane below where you plan to put your epoxy - this provides for a nice mechanical grip for the epoxy to hold onto.

On the subject of epoxy I have also thought of a good way to ensure that any epoxy that might run into the plugs holes does effect the usb plug. Borrowing on what someone else posted about spraying silicon on your usb plug - do this and then carefully insert the usb plug into the socket before applying epoxy. Leave the plug in during the full epoxy drying time and then remove. The idea being that with silicon on it the plug will not adhere to any stray epoxy that might get through the holes, and, since no two bodies can occupy the same space in time, the plug provided a mold to ensure that any stray epoxy does not affect further insertion of the USB plug.

put me down for 'poxied

hardest part for me was reattaching the screen ribbon

glad you mentioned this. I ran most of the epoxy along the sides. It does want to enter those holes. I actually pulled and reinserted the usb plug during the dry time and it saved me some trouble. That said, it is possible to get inside the port with the smallest screwdriver to do SOME damage control after the fact if the epoxy enters the port.