I've had a TomTom GO710 for 3/4 years working fine I attach it to my SEAT Altea with a built-in cradle hard-wired to the car which allows 'voice instructions' to come through the cars speakers and the mobile-phone etc...
I also use it on other cars using the cradle on the windscreen attached to the cigarette lighter.
I've recently updated the maps with no problem !!!
I thought I'd then try updating the Navcore to get a more up-to-date look/feel on the TT710. I managed to find a couple of different Navcores that do the job.
However, whilst the TT works fine attached by my mains adapter and the cigarette-lighter charger - it wont work when I attach it to the built-in cradle in the car.
It keeps bombing-out and reloading, basically looping.
Where the cradle connects to the tt there is a row of connector pins, they become broken from the board and lose contact with the main board, i have done several repairs, the solder points are extremely small and its very easy to damage beyond repair, if you cant solder and dont have a very small iron/tip then find someone that can, otherwise you will probably break it altogether.