Try this: while unplugged, press the reset button on the bottom. If your Tom Tom is turned off, you may not notice anything until you turn it back on, But first plug it back in to your power source and charge it up for a while. Then try to power up again. You could also try another USB cord.
I think I have the same problem, but after doing this reset/recharge trick for the past few months my Tom Tom finally kicked the bucket. It seems that the green charge light is not fully on and seems to flicker. I believe the problem is internal, either with the USB female connector or something else inside. If anyone knows more I'd also love to find out.
Gene B
November 2010
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