Volca Sample mute & function buttons are not working

[itsobba]

Hello, I have checked the forums and net but couldnt find a solution. my volca's mute and function buttons are not working. only these ones as rest of them are working without a problem, and sometimes mute button works with a huge lag, like I have to keep pressing it for like 40 seconds, but it doesnt always work. So I assume it is a hardware issue where I have to dismantle and clean it, or do you have any other solutions to this? thx in advance