LMDE update, now have boot error

Hello All, My LMDE laptop just went through a huge update, and now can't boot. Every grub boot option returns "error: no such partition". There are quite a lot of stories on this, and many suggest using grub rescue mode, then use "ls" to see what partitions are seen. This doesn't work, always returning this same error message. I guess I will have to boot from a rescue disk, but not sure what I then need to do. Any help appreciated. Cheers, -- Regards, Terry Duell