Tom Tom 720 Gone Quiet On Me?

[Marvindodgers]

Looking for a bit of help. My Tom Tom 720 has suddenly gone silent on me, i.e. it has given up on speaking the directions or giving speed camera warnings. Before anyone asks, I have checked that the volume is up and that I havn't turned off sound. I can make the test signal work in Voice Preferences and so I know that the speaker has not blown, but that is the only sound I can get it to make.
I've tried pressing the reset button in the base and this has had no effect.
The only other option I have is to restore factory settings and see what happens then. Before I do that and lose all settings and information I have added, has anyone got any ideas?

[Chief993]

This happened to me a few years ago after leaving the 720 in a very hot car, cut a long story short, leave it on until it goes totally flat, plug charger in, hold in reset button then switch on charger then switch on 720. After about ten seconds release the reset button & hopefully should boot up ok. Mine has been fine ever since, if that doesn't work looks like a complete reset.

[Marvindodgers]

Thanks, I'll give that a go this evening.