Hi all.

I got my N900s in 2010, so the USB dangers were well known to me beforehand. Accordingly, I took great care of my USB port, and it's been fine up until now. In the last couple of weeks I noticed it wasn't charging at work where I have it plugged into my PC. It also wasn't syncing. I then noticed Windows was telling me the USB device wasn't recognised.

Strangely though, it was charging from wall chargers fine. I then discovered the same device not recognised error at home. I tried updating Nokia Suite, to no avail.

I figured that one or both of my D+/D- pins had come loose, and the VBUS and GNDs were probably fine, hence the charging from wall chargers. The port itself feels solid. So I research USB repair on here, and disassembled my spare N900 for practise. I figured all I'd have to do is reflow the solder on a cracked joint to fix my issues (as shown here)...but then I saw how constrained the work area is once you prise off the memory card board. I cut away some of the EMF shielding and figured if I filed down one of my tips I had a chance of pulling it off.

I then had a brainwave - I plugged in a USB cable to my main N900, stuck a multimeter probe into the full-size connector, then used the test pads under the battery to check continuity.

Unexpectedly, D+ and D- are fine.

I decided to disassemble just in case, and low and behold, the joints look fine too. So I'm lost.

Has anyone got any ideas why my N900 isn't being recognised any more?

EDIT:
I should also throw in that when I switch it off and load up bootmenu, using the console option I can see kernel messages, and I can see that the battery charges fine from my work PC via USB.