hello buinu
i checked the batteries also for any orrosion but every thing looks fine also contacted mike martin and he suggested for me to take my k to be serviced then i spoke with someone at sweetwater that suggested to check the small batterie that looks like a small watch batterie inside the keybord not the AA ones and i have to say i was pretty surprise to know that there was such batterie inside so i went ahead and opened the board but couldn't find any batterie inside does any body know any thing about that .
by the way i'm very use to open my keybords without any problem and i 've chaged that type of batteries inside my korg t3 couple of time but i can't find any batterie like that one inside my k2vx any where.
any help
thanks
eddy

Hey eddie,
I've never been inside my k25s but this is the first time I have heard anything about a battery other than the AAs. I thought the K2 and K25 were similar in that regard, however, Mike M. does work for Kurzweil and knows the equipment. So, I would take his word for it and put the unit in for servicing. Let us know what you find out.

I never heard of a second battery or battery pack either. Perhaps there is an internal battery back up that stores RAM objects containing ROM keymaps(not samples), but I cant find anything about it in the manuals.
Having an authorized service center take care of it is the best thing.