!
error Chamberlain
Error Code 3 UP / 3 DOWN
The battery status LED is constantly flashing green. Battery backup charging circuit error.
? What Causes This
Battery backup charging circuit error.
✓ How to Fix It
Replace the logic board.
Source: page 37 of the official manual
From the manual
This error code appears in:
Chamberlain Chamberlain Garage Door Opener