Thanks for your input, everyone.
Someone should expect a phone call tomorrow...
I think the laptop is a gonner. I've ordered a new one, which should arrive within 5 working days. How will I survive??
I appreciate your suggestions, even though I don't know what a motherboard is or that I can't really search anything on this old old just-came-back-from-retirement-in-a-box laptop.
Hopefully I'll be able to recover the stuff on the hard drive (?) at some point, such as letters/documents and pictures.