A quick look around the net confirmed that there is an inherent weakness in the LX50's cable in that the end that joins on to the back of the odometer on the dashboard is made of plastic and tends to snap.
I was PRAYING that this was the reason for my problem. But sadly it wasn't. As you can see from the picture it had in fact sheared off inside the cable housing leaving me with a pretty irritating problem.
https://scootayblog.files.wordpress.com/2015/11/bustedspeedo.jpg?w=283&h=179
If just the inside had broken then I could potentially have just bought a new one and threaded the cable inside through.
However, now I have to completely remove the cable and replace it. A total pain because apparently there's rubber grommets and things that it's very hard to thread it through.
https://scootayblog.files.wordpress.com/2015/11/img_3827.jpg?w=320&h=238
I've just ordered a new one off Ebay (hopefully it's the right one)
http://www.ebay.co.uk/itm/400717109791
When it comes I'll put up a post and video of me trying to replace it.
If anyone's got any advice on how to do it I would appreciate it.
Will.