Contact pad on R5 drum machine.

[batchas]

Do you know how I could get them to work. They are too old and do not contact anymore.
I tried to put some lead pencil on the contacts (I did this with success on my SCI sixtrak a long time ago) but it did not work here.

I also broke one button accidentely by cleaning the part with the buttons and cannot glue anything on this material.

Maybe there is a workaround possible to get the contact to be made, without even the use of the plastic buttons (third photo), but I do not even know what material to use to make the contact to switch correctly (first photo): it would not bother me to have to use a stick or whatever in place of the button to get the switch to act.

I hope you know what I mean. As 1 button is broken now anyway (third photo), I am ready to take something else in place of these buttons (second photo) to make the contact on the fly.
¨
First photo:

Second photo:

Third photo:

Sorry for the horrible photo quality!

[batchas]

I got an idea.
I don't know what material it is which allows the connection/contact on the round part of the button that I destroyed with the pads on the green board, but I'm gonna fix it on a stick/pen. And I'll try if it works.
I have some doubts because most contacts on the green board were not working anymore and that's why I opened it, but worth a try!