My macbook is suddenly refusing to start up, either going onto a grey screen with a no smoking sign on, or a grey screen with the apple on. It then goes onto a black screen with white text on and dies. Holding down shift (safe mode) didn't work, help!

Growing old isn't for sissies...the past couple of weeks have been hectic but all one can do is keep muddling along.

When you say sorted out, do you mean by reloading/installing the Mac OS X you have recovered operation? That is good news, congratulations.

At this point it would be a good idea to look into an external hard drive so you can backup and have a bootable source should things get messed up again...a great source of drives is from the Mac specialists at OWC, http://www.macsales.com I use their Mercury Pro Elite drives and have been very pleased with them.