The sound on my tom tom decided to stop working whilst i was driving but luckily i could still view the screen.
It’s still within the one year warrenty so i phoned the shop where i got it from, told him the problem, apparently its a common problem.
Turn device off and make sure its still plugged in, turn it on holding it for ten seconds then you should hear the drum roll. I didnt hear it so he said try again but hold if for longer, so i did and it made the drum roll noise so working again now. Hope this helps if you encounter the same problem.
Never happened to mine, but a lot of TT problems can be solved with what is known as a soft reset.
Ken.