Maybe leave it a bit and then try again? I guess it must reboot every time the engine is switched on so worth a try. If not then might need plugging in at a Citroen garage.

 

This sounds a bit of a catastrophe.
Depending on what is on the USB stick, the firmware update procedure might have attempted to initiate and then stalled.

Its not clear to me if you done the following :
1 turn off ignition,
2 remove the usb stick
3 wait 5 minutes (my guess) to give time for any software recovery routines to clear
4 turn on the ignition.

 

Left it for an hour and when switched on all returned to normal, monkey magic i guess.

 

Glad it's fixed! It's a worry when so much is operated via the touch screen for it not to work.

 

I've noticed since yesterday that the screen is suddenly more 'laggy'...for instance, in any screen pressing the button on the end of the wiper stalk normally enables you to 'toggle' through the trip computer screens (trip 1, trip 2, current figures) You can still do this, but now the screen briefly goes back to the previous screen in between toggling through. Also, it's just not as snappy anymore. I want to update the firmware, as although I specifically asked the dealer to do this on the last service it wasn't... :evil: I have the file downloaded, but have cold feet about installing it in case it all goes bad...

 

Take off the positive side to the battery wait 5 secs and replace the lead, this will reboot it. Easy peasy..