I love this forum - you guys are the best! Thanks for all your replies.
Thanks doylebros for the links - I was quite daunted initially when I saw the pics in the first link but I presume I only have to do up to the bit where the screen gets taken off?! I got lost a bit in the jargon in the second link...
Re. a firmware upgrade, how do I find out what firmware I've got? And how do I get the upgrade? This sounds promising although I've also heard about firmware upgrades "frying" the unit ...
Sounds like I could try a firmware upgrade first then, if that doesn't work, try a new screen ... ?