So, after quite some time, I finally have my N900 (which charges perfectly fine, but doesn't seem to have data connection at all - which is an issue as I need to reflash the thing but I can't...) taken to a repair store and looked at. Turns out that the problem isn't with the USB port breaking from the mainboard - in fact, they resoldered the port, and, in USB flash mode, it still wouldn't be recognized on the computer (the computer, in either Linux or Windows, refuses to recognize the device as being there - lsusb doesn't show anything, etc.). Tried this with several USB cables and ports - same results. Any clue what's going on?