Since SHARC keeps coming up as a reference, and since their site references primarily Garmin brand repairs with a few Magellan thrown in, I figured I'd call them today to see whether they really do repair TomTom units or supply parts. Unfortunately, they do not provide any phone number for their operation... just an AIM/Yahoo screen name for those message services.
To the OP - one thing is clear... you will not be able to buy just the part to replace it yourself. On SHARC's main page, they state "Due to liability reasons, we DO NOT sell parts." It's also pretty clear that they're operating this business out of someone's house, since they also note "Due to local ordinances, we are unable to provide local drop-off and pickup service."
I have sent the following my email to the site owner's published domain contact address to see if there is any response:
I?m one of the moderators for the tomtomforums.com site, and we keep running into questions about TomTom repair in the U.S. Unlike the UK, where there are several shops that will tackle TomTom issues, I am not aware of any in North America.
Your web site seems to focus heavily upon Garmin (?G-brand?) with the odd Magellan reference. Do you repair any TomTom units, and if so, to what level and which models?