error 0210: stuck key 28 IBM 390E

Hello,
I get error 0210: stuck key 28 when booting my IBM 390E. I was told to try resetting the bios jumpers by takeing the jumpers off one at a time and put them back on it resets the cmos? there should be one labeled cmos reset or bios reset. Im having trouble taking apart my laptop and finding the jumpers. any and all help is appreciated. thanks.