I really hope someone here can help me out. I recently purchased a Rocktron Piranha preamp and unfortunately, I got scammed - the unit's left side controls (responsible for program changes, distortion type, etc.) just don't do anything. I've measured those and the buttons themselves do work. Has anyone had a similar issue? Any advice on maybe how to fix this? Those preamps are really rare and kinda expensive for my location and I would really like to avoid having to get another one.
I think that realistically, the only option you have is to take it to a shop and see if they can fix it. If a controller chip or something like that is fried, there's no way of fixing it yourself unless you really know how to analyze and repair digital equipment. I've had problems with digital gear before and unfortunately, sometimes it's not something you can easily fix yourself. Especially in your case where the buttons aren't responding.