The blinking green on the big button is the bad news. It indicates it's trying to update the firmware for that button, and apparently that's not working. It seems likely you'll need the controller chip replaced on that button. That is quite easy on the early OLED button panels as each buttons controller was mounted as a removable unit, the later versions require a surface mount replacement.
If you have an earlier OLED panel you can try reseating the big button module, perhaps it just has poor contact( liquid ingress into the connectors and other sturdiness upgrades is precisely why the later versions came out, aptly named "Splash" 3.0 OLEDs.