Help please, I have a 63 superb and had it a couple of years now, only recently I have used the sat nav in it. Was working fine came to go out in car and the unit said it was doing an update/ download it has now done the download but I have a black screen saying download complete but searching for swl screen. The unit will not turn off at all and have now got a flat battery. I have done a reset but nothing helps. I can not get anything on the screen at all. I’ve taken the unit out at the minute so I can still use car and not keep getting a flat battery. Any help greatful

You must reflash the unit with latest formware. Take it out and post picture of the upper case label.