how can i get my TOMTOM XL 30 to charge?

I get a similar problem with a 910.
Does not charge from car unit or base station despite green LED being lit, when powered up I get warning the battery is flat so for some reason the power gets to the LED but not the rest of the circuitry?

Just incase I replaced the battery but the same symptoms persist.

Any ideas? perhaps a voltage regulator chip has gone open? but how to identify and replace this if that is what it is?

Graham
March 2010