I have just one key that worked for a bit and then stopped yesterday. I pulled out my multimeter and tested connection from the switch, and it seems to be working fine. Is there a way to test the surface mount diode? I just ordered a new pack of them to try to replace it, but I wasn’t sure if that is even really a part that can fail.
A quick duck search pointed me at https://toolsweek.com/how-to-test-a-diode-with-a-multimeter/ . It’s been a long time since I needed to test diodes, but the instructions seem to match what I’ve done before.