sat nav mio C510 or C710?

Have you taken the back off and checked the battery is still plugged in. It is not difficult to open up, 4 screws in the back under rubber bungs and 2 in the bottom. I took mine apart for the first time last week and replaced the battery for one from an ebay shop. The only thing to watch is that you dont loose the on off switch extension which will probably drop out when you open it up and will need re alighing whith the switch when reassembling the casing.

ricky
September 2009