For those in warranty:
There are a few N900s floating around nokia repair's contractors in the EU. It is advisable to supplement the repair note with a request that you don't want anything other than a repaired/replacement N900.

NB. This is NOT the same as a nokia repair centre, which are retail outlets, licenced by nokia - these will swap your N900 for a symbian device while the mail-order ones are less likely to.

If you're out of warranty:
Learn how to solder, even if it still works!