Kurzweil PC88

On my digitial piano, there is only one key that will without any reason, jump up in volume tremendously with no consistantcy. Occurs randomly, sometimes it does, sometimes it doesn't.

Can anybody help me?

I'm sorry, I can't help you, but I'm hoping you could help me with answering a question about Kurzweil's action.
I heard it was really good, but the thing I really want to know is the weighth... Is it heavy or more on the lighth side?

Maybe some dust or water on the contacts inside? I had that briefly on my YPG-635 but it went away like 5 minutes later. Could try opening it up and seeing if there's anything under that key...

Usually this behavior is typical of dirty or worn out key contacts (sensors). If you feel comfortable with cleaning them yourself, you can try that but otherwise take it to an authorized service center. Generally, the key contacts are difficult to get to.

Vid W, Kurzweils tend to be a little on the light - synthy side but it varies from keyboard to keyboard.