Hi Richard,

Have you tried turning the KN 'off' and then holding the relevant buttons whilst turning it 'on' (sorry I don't know what these are but it should tell you in the manual). This will return it to factory status which I am sure you will already know about this little trick. Worth a try anyway.

Or, does the screen have a 'Contrast' control? If so, maybe this is set too bright and needs turning down a bit.

Just a thought!

Audrey