When an LG washer has an "LE" error (that will NOT reset after unplugging the washer) in most cases the HALL EFFECT SENSOR is at fault.
Since you've replaced the HALL EFFECT SENSOR---the next most likely cause will be a broken wire in the WIRE HARNESS leading to the sensor.
When testing the continuity of the sensor WIRE HARNESS---it is important to flex the harness while test continuity.
It is not unusual to find a faulty/failed wire within the harness---that gives continuity---until it has been flexed/moved.
If a wire has been found to be at fault---the damage will usually be found (if looking at the photo of the harness in an earlier post)---under the white tape of the harness---at the 5 o'clock position on the photo.
If the WIRE HARNESS is not at fault---then the MAIN BOARD is the next "suspect" (very rare).
To properly test MAIN BOARD output:
Remove the rear access panel
Place the test meter leads into the plug (do not disconnect the plug) connections BLUE & GRAY at the HALL EFFECT SENSOR.
Plug in washer
Press Power button (only)
The test meter should show: 10 to 15 volts DC (direct current)
If not---replace the MAIN BOARD.
NOTE: When ordering a new MAIN BOARD for a WM2277
washer---ALWAYS provide the SERIAL NUMBER.
Several production changes were made to this model washer before it was discontinued.
There at least 3 different MAIN BOARD part numbers for the same model number washer.
Only a SERIAL NUMBER assures receiving the correct MAIN BOARD.