LED flashing on wall control, not in lock mode

Hello. I have a Chamberlain LW600WFCi 3/4 hp garage door opener, which up until recently, worked great. What has happened is that all of a sudden the LED on the indoor wall control has started flashing, and it will no longer open the door. In fact, it won't turn on the light either. The outdoor keypad and vehicle remotes all still work fine, and the safety beam/sensors are working fine also. I've tried to hold lock button for 2 (or more) seconds, but no result. Another thing, is that the ADJUSTMENT button (rectangular button in between the up and down arrows, under the light shield on the motor unit) is perpetually flashing. I'm not sure if it was doing that before or not. Just before I go out and buy a new wall control I wanted to make sure there wasn't something I was missing. Any ideas? Thanks.

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