In addition, some of the keys are dodgy - I get audio clicks from them, they sometimes retrigger the same note, or fail to trigger a note at all.
I'm presuming that this is all caused by dirty pots and contacts, and that it is possible to fix it by using some sort of spray contact cleaner. But I know nothing about repairing electronic equipment, so ...
1. Is my diagnosis correct - is it just a matter of cleaning the relevant pots, contacts, etc?
2. If so, what is the best product for cleaning the pots and contacts?
3. Can anyone give me step by step instructions on the best way to do it, or point me to a good guide for how to do it?
4. Am I insane to think of trying to do this myself?
5. Oh, and the relative keyboard tuning seems to have slipped (i.e. C3 is slightly out of tune with C4 and so on). Is there an easy way to adjust the individual tuning of each keyboard note?
Any assistance will be gratefully received

Cheers,