<<<I am getting a Er FF code and I replaced the freezer fan but the new fan is not spinning and after a few moments I get the Er FF code ageain.>>>
The "ER/FF" error occurs when the Main Board does not receive signal feedback after 115 seconds---from the Freezer Fan Motor sensor (internal rotor position sensor).
Test for voltage from the Main Board-to-the-Evaporator-Fan-Motor (Freezer Fan Motor)
Remove the cover---at the top of the refrigerator.
With a good flashlight (and a magnifying glass if needed)---locate the plug on the Main Board marked: "CON7"---and remove/pull off the plug.
Using a Test Meter---check the voltage (on the Main Board) marked: "G" and "V"---should have about 12.8 volts DC (or anywhere from 7.5VDC to 16VDC).
NOTE: The reason for the varying voltage---is that there are two fan speeds controlled by the Main Board.
At start-up (warm refrigerator)---the Fan Motor will run at HIGH speed.
After the temperature in the freezer becomes colder---the Fan Motor runs at REGULAR (slower) speed.
Activating the RAPID ICE (Optichill or Express Freeze---if available)---will cause the Fan Motor to run at HIGH speed for longer periods (usually up to 24 hours).
Another interesting thing to be mindful of---if the freezer is at or near set temperature (fan running at REGULAR speed)---and the freezer door is opened---the Fan Motor will *stop* running.
If the Fan Motor is running at HIGH speed when the door is opened---the Fan Motor will run at REGULAR speed (while the door is open) rather than turn off.
Test the voltage at "G" and "F"---should be 2.5 volts DC (note: older LG boards *may* be marked: "G" and "L")
Replace the Main Board if no voltage.
This is an older model/design LG refrigerator.
The original Evaporator Fan Motor (4681JB1017D) has been replaced by an improved Motor (4681JB1029A)---beginning April 2002 (Serial Number 204KRxxx and higher).
This new Evaporator Motor has better sealing to protect the Intergrated Circuit (tiny circuit board inside motor) from moisture.
Additionally---the Main Board was changed/improved.
The correct replacement should be (6871JB1259D)
Typically---as years pass---there may be a dozen "corrections" done to the Main Board. Most of them are software updates---and not all updates are published as a Service Bulletin
Some "tweaking" of the software is so minor that it's not worth the time & effort publishing anything about it.
One of the biggest improvements---was the addition of larger Relays (on/off switches).
BryanS mentioned the possibility of a "wire problem" that is "unrepairable".
While this is certainly a possibility---it is the least likely.
Two other areas that should be checked...
1) Freezer door "lightswitch" (6600JB3007B)---As these switches become older---they're prone to intermittent failure.
2) Plugs and wiring at the freezer door hinge (top)
Yea LG can be tricky. The problem working at Sears I didn't always get to go back on the refrigerators I ordered parts for. I believe the tech that went back and put the main board on figured it may be a wiring problem in the cabinet which isn't serviceable. Also possible that the old main board took out the new motor and when he installed the main board it didn't work because maybe the new motor is now bad. I wish I had a definite answer but I really didn't run to many of these. Does the motor run at all? You could check voltage on the board but you need those needle point leads. They usually have a schematic on the back of the fridge. Those fans are typically DC voltage. I think they have 3 pins on the main board for the evaporator fan. If I'm not mistaken the connectors may be labeled on the board. The left and right pin on the connnector I believe are voltage to the motor and I think the middle and right pin are feedback voltage from the fan motor. It may be left and middle is feedback voltage. It's been awhile.
Well technically you don't have to have needle point leads. I have taped sewing needles to my regular multimeter leads and did it that way. They are kind flimsy.