[PaulBoy]

The wife's K750i works perfectly apart from the "joystick" which isn't very smooth & is reluctant to go up from the central position - is it possible to lubricate it in some way (WD40 or something) or is a job best left to a qualified technician or someone?
TIA ... Paul

[Para]

best to use compresed air, if anything,

but if your want to, its usually dead skin and dirt that cloggs them up, so if you able to open it and rebuild it, all you need to do is clean the contacts..