Right arrow button/ repairs

Hi my MPC1000 right arrow button doesnt always click (needs two or three but sometimes works first time).
is this something easy to repair or check?
Also my q link sliders have never worked (2nd hand purchase) and what can i look for when i open up the machine to see what is wrong. the buttons on the q link light up but the sliders send no data.

I hope someone can take the time to offer me some guidance. Many Thanks.

Open up the MPC and spray the tact switches (and Q links) with Deoxit, this often fixes problematic switches. Otherwise, buy some new tact switches and replace the existing components. If you are not experienced with soldering electronic components, get a pro to do it for you. You can buy all the components from MPCstuff.com or if you are happy to buy in bulk and know what part numbers you need (search the forum), you can get them from mouser or farnell etc.

Where are you based?