On my old N900 (warranty already expired) the USB port broke...

Fortunately I found a company which repairs it (soldering a new USB port on the board) for under € 100,-.
I'm very happy that this was possible because the other alternatives I requested on serveral calls toward service centers was at least 3-4 times more expensive offered.
Here my recommended contact (with his permission) for such repairing our old beloved N900 with broken USB-Ports:

Mr. Bernhard Kirchschläger
Mobiltelefon-Service-Center ( M-S-C )
Wiener Bundesstraße 46
4061 Pasching/Langholzfeld
Austria
Phone.: +43 (0) 7229-22316-11
Fax.Nr.: +43 (0) 7229-22316-22
Mobile: +43 (0) 660-4560110
Web: www.m-s-c.at
Mail: bk@m-s-c.atry happy

Regards, Kyros