The only button that works on my Quiet Partner III is the Cancel button

I have a Whirlpool Gold Quiet Partner III GU1100XTLT1. When I push the "Cancel " button, it lights up and I can hear a motor running. The light and motor turn off after about a minute. None of the other buttons do anything - they don’t light up or cause the dishwasher to do anything observable. I have tried resetting it. I’ve tried replacing the control board with a used one I found on Ebay. It displays the exact same symptoms - no buttons except cancel work, and cancel just causes a motor to run for a minute.

Any ideas on what else I can try? I’m considering replacing the control panel, but it isn’t obvious to me what the part number is, and I’m a bit afraid to just buy something blindly on Ebay.

Some bad news… it says control panel no longer available. Part #1 came in biscuit, black, and white.NLA

https://www.appliancepartspros.com/control-panel-parts-for-whirlpool-gu1100xtlt1.html

Maybe epay or some other site might have one.