Kulp K16A-B - Push Buttons for Navigation on Display not Working

[retro]

I have a Kulp K16A-B and the 4 push buttons for navigation using the display have stopped working. I've updated the OS and tried another memory card but still not working. Any Ideas?

[CaptainMurdoch]

I'd say try pulling the OLED display, but that would mean you couldn't test.  If you have another OLED display, try swapping them.  There have been some issues with older OLED's messing with the i2c bus and causing issues, maybe yours is affecting the I/O expander chip which the buttons are connected to.