Hi Chaps, don't worry mr dead satnav is here
Sorry I didn't catch this thread before
I'm almost certain, ekinlock, the stealership disconnected your battery when doing the rear bushes / mot and on reconnecting it nuked the satnav; or they disconnected it before the unit had shut down. Whenever reconnecting the battery forum advice is to have the sidelights on to prevent a surge. It is also vital to leave the nav to shut down for a couple of minutes before removing the battery terminal or it WILL die.
Mine went in for a gearbox and as the battery was dead the mechanic jumped it and I reckon that nuked the nav computer.
FYI the disc drive is actually the nav computer, the dash unit is just for your inputting controls and the screen is driven by the disc drive.
If the screen is dead it COULD be you need a replacement screen; or it COULD be you need a dash unit; but most likely is the computer is dead. Poor little fella!
I have my old screen and dash unit because they weren't compatible with the computer I got. If components aren't compatible you can usually tell because the Renault logo displays or a clock in the corner.
Your radio / stereo bypasses all this so should always work. There is an easy way to enter the stereo controls via the stalk -- yes!!! Its true!!! And it works
... so don't worry about disconnecting the battery
Any other questions just shout -- btw the other potential cause of a fault is the arial but that's just where the nav can't find signal and pretty obvious.