I'm guessing you have electronic indications for both speedometer and tachometer ??
First thing I would do, is to find out what fuses control these and remove them for 15 minutes or so then reinstall them and see what you get for indications .
I don't know if this applies to the R1200 bikes or not, but with the R1150's, after you reinstall the fuses, with the key in the ON position, open the throttle completely to the stop two times slowly .
Hope it's a simple fix .
There's a site for oilhead bikes, R1150R.net, they have sub forums for the 1150, 1200, R1200LC, Rockster, GS, R NineT .
Free to join and quite helpful, solved what few issues I've had with my R1150R