rns-d navigation fault

[ukinv]

Im new to the site and already need help.

i have a rns-d naviplus unit. it was working fine untill 2 days ago. the satnav froze. i had to remove the fuse to turn the sound system off. since it froze, everytime i enter destination the unit switches off then back on . no matter what i try and do.

The cd and radio still work, the satnav works if i manually enter location. but wont store anything.

is there a way of doing a reset?. i just dont know what else to do .