Finally after more than 2.5 years my USB port stopped recognizing charger and computer. Not that I totally unexpected that but of course it is always unpleasant surprise.

I just bought a new car USB charger that was pretty stiff to plug in (I did bend the lock pins before first use.) After very first attempt it did not start charging. I confirmed with my "known good" charger the same behavior. So USB port is the issue.

I opened up the phone and did not see any damage on USB port by looking with magnifying glass. The USB port frame solder joints were solid. It must have some/all of the 5 small signal contact pins detached from PCB.

I took it to my workplace where I have a hot air gun, solder and flux. I tried first to remove the whole port but it just didn't want to come off easily. I was scared I'd destroy the PCB by trying harder, so I did just apply extra flux to the existing solder contacts and reflowed the existing solder. When I got home I reassembled the phone and to my relief my USB port is working again.

As a summary I'd say that it is possible to fix a USB port as long as the tracks on PCB are not torn off.

The tricky part with hot air is to protect the other areas on the PCB from excessive heat, especially the little hanging satellite PCB piece that holds the SD card holder and camera flash LEDs. Also I did remove the camera module from the motherboard before the repair. (I figured the camera can not tolerate much heat.) To remove the camera module I used three strips of a thick paper I cut from a business card... (Nokia disassembly instructions advice to use a special camera removal tool, which of course not many people has.) Still the plastic spacer with double side tape attaching the SD card reader to the top of the main PCB did melt in some locations. If I was to do this again I'd remove the plastic spacer from the satellite PCB.

In case you have a USB port that is intermittent or not working but still attached to the motherboard you might want to consider this method. No guarantee it will work for you but at least it did for me.