Diagnosis
The blinking lock light means the washer isn't sensing that the lid is properly closed and locked. It's a safety feature. On this top-loader, the issue is almost always the lid lock assembly itself failing, or the little plastic hook on the lid that engages it being worn or broken.
How to Fix It
First, do a visual check. Look at the underside of the lid. There's a small, white plastic hook. Make sure it's not cracked or missing. Then, look into the lid lock mechanism in the washer frame. You might see debris or a broken piece. Try closing the lid with firm, even pressure. If the light keeps blinking, the lock assembly (part # 6320ER2001A is common) likely needs replacing.
If That Didn't Work
Before ordering the part, unplug the washer for 5 minutes. This can sometimes reset the main control board's error state. Plug it back in and try again. If it still blinks, it's almost certainly the physical lock mechanism.
Heads Up
Don't try to bypass or manually trigger the lid lock. The washer won't agitate or spin with an unlocked lid, and forcing it can damage the actuator or the main control board.