The lock button on my car key fob hasn’t been working for ~ 6 months. I was looking at buying a new key fob for between $9 to $35, but something told me to take it apart.
Some isopropyl alcohol, a used toothbrush, and 5 minutes later I discovered some kind of sticky blue goop had infiltrated my key fob. After a quick brush down and slight emersion of the lock button, my key fob is now working again.
Ah I did similar with a broken furnace logic board from 2004. Carrier still made the boards, but wanted $250 and none of the components used on the dang thing justified that besides them knowing most people have no choice in the moment.