The backlight lamp in our 1994 Dimension 1 Colisuem is no longer working. I have tried unsuccessfully to find where, how or what to replace to get it to work again. I don't even know how to get to the backside of the keypad. Anyone have any diagram/instructions on this?

pry it off, an try not to crack anything (shell or topside)

If it's just the backlights, and not the actual LCD, they're easily replaceable- call D-1 for a dealer near you.
1-800-345-7727

The just screw in 1/2 turn (camlock), and lock in place. Directly accessible from the rear of the topside.

Again, thank-you for your response. Sounds easy enough - you'd think they would say so in the owners manual or something! I really appreciate the help from SpaForums.com.