Roland TR6s unresponsive buttons fix

A friend gave me his Roland TR6s to see if I could fix a button that was not responding well.
The first thing I did was opening it and cleaning the contacts with isopropyl alcohol, but that made things worse, so I had to put some conductive paint on the button contacts.
This video is self explanatory (i think), so it doesn't have any audio. You can watch it while listening to whatever you want, instead of some horrible stock music.