I read it was more reliable to scratch the board from enamel around the plug and re-solder it widely to allow better reinforcement than adding glue as glue is too soft and elastic. I'll give a try these days on an old n900 bard. Done and working! I explained how I did here And by the way, don't throw your n900 with broken USB, fix them or send them to me, I got addicted to save them