Chamberlain Opener acting very bizarre (randomly flashing light and control panel)

The other day my Chamberlain Opener (Model 940ESTD) starting acting strangely. It is in almost a constant state of the light and control panel flickering and not in a good way. This is not some kind of rhythmic warning message. It's like Gremlins are running around in both the opener unit itself and the control panel. When this is occurring, there is almost nothing I can do to stop it. I've tried covering the motion sensor. Nothing. I've tried stepping in front of the beam at the bottom of the door. Nothing really works except unplugging it. It does beep sometimes while unplugged. If I plug it back in, it immediately starts going haywire again. When it's acting this way (currently that is about 95% of the time) I cannot always open and close the door from the panel, but I can from the outdoor remote key pad.

I was thinking about replacing the battery. Outside of that I really have no clue what to do.

The opener is about 5 years old, and I have never replaced the battery.

Any help would be much appreciated.

-- Gary

Answering my own question... the logic board was faulty. I called Chamberlain, and they told me to purchase the board and sent me video instructions. Piece of cake.