HP-28S Keypad Issue

[BitWiz]

I recently acquired an HP-28S and everything is working fine except for the bottom row of the keypad. The [ON] key must be wired differently as that works no problem.

However, I am able to get the bottom row to work perfectly and even pass the keypad test if I press any where on the bottom plastic frame of the LCD.

Has anyone else experienced this issue or have any ideas. This calculator is difficult to open and service.

Thank you,

Mike