Lg LFX23961ST not cooling, already replaced mother board and still not cooling top and bottom

please specify fan for what . thanks .

You have a problem with the ice room fan motor. It will not send freezing cold air to the icemaker. You will need to have a qualified technician replace the fan motor.
Good luck

You went the wrong way on setting, go to lower setting,this should help from freezing.

A sound deading kit.

could be bad fan. sometimes the sensors on the them go bad

LG LFX23961ST Support Manuals Warranty More LG

I just used the link above to get the Manuals on your LG. On page 31, they did the following CYA statements...

The defrost timer will click when the automatic defrost cycle begins and ends. The thermostat control (or refrigerator control, depending on the model) will also click when cycling on and off. Rattling noises may come from the flow of refrigerant, the water line, or items stored on top of the refrigerator .
Your refrigerator is designed to run more efficiently to keep your food items at the desired temperature. The high efficiency compressor may cause your new refrigerator to run longer than your old one, and
you may hear a pulsating or high-pitched sound.
You may hear the evaporator fan motor circulating the air through the refrigerator and freezer compartments.
As each cycle ends, you may hear a gurgling sound due to the refrigerant flowing in your refrigerator.
Contraction and expansion of the inside walls may cause a popping noise.
Water dripping on the defrost heater during a defrost cycle may cause a sizzling sound.
You may hear air being forced over the condenser by the condenser fan.
You may hear water running into the drain pan during the defrost cycle.

I bolded the statement. Sounds like you are going to have to get used to the sound.

Semper Fi,
Z

replacing the mother board is the option that a repair person uses if they are authorized to Repair LG parts. on the back of the unit there is a square plate remove it and you will see the mother board. on the bottom right of the mother board is the culprit fuse. its soldered in. you will have to go to an electronic store and get another fuse and either replace it or have them replace it for you. i went to radio shack and picked up the fuse holder, soldered it in and in the future will only need to replace fuse.

Unplug the frig, wait for about five minutes then plug it back in. The display should reboot to the default settings

I don't think replacing the filter had anything to do with your problem.  If the ice maker is working then the freezer is OK since they have the same cooling source.  I had the same problem with this model refrigerator six months after I got it (in 2/2007).  The cooling in the refrigerator section failed.  The refrigerator fan and the air duct as well as the mother board were replaced.  A year later the ice-maker fan froze up. It and the housing were replaced with improved models.  The mother board was also replaced again due to software changes related to the ice maker.  This model is also part of an Energy Star/LG case agreement to modify the circuits and provide a lifetime annual rebate payment.  Check it out and register on the LG web site.

HI. you will qualify only if you installed a genuine LG part and, it was installed by a certified LG tech. That's the only way to qualify.