strange boot problem

[O. Sinclair]

Friends,

being on Kubuntu 12.04 I have for some time now experienced a strange 
problem I can not solve and searching has not given me any hints on.

When I choose "recovery boot" option the boot will start, then the 
screen goes blank and - nothing.

I suspect I am missing the "menu" that normally would come up but can 
not find any info on package, how to activate or what.

Screen brightness is not the problem.

Hope someone can help as I want the option, though rarely needed.

Kind regards
Sinclair