LG GS-B680WL Linear Inverter side by side fridge freezer nothing working, no motor, no fans, no interior lights, nothing!

clear the air way for circulation

What is the model number and is the compressor kicking on?

If you're lucky, it's just the capacitor on the motor. Have it checked, but be prepared to need a new compressor.

Change out your evaporator fan motor in the freezer, and while you're at it, toss out any frozen zombie heads you might have stored in your freezer, just to play it safe.

The error code appears when there is an abnormality of BLDC FAN Motor for Freezer. It circulates cold air from the freezer to the fridge to allow cooling. Check the motor wiring harness for poor connections. If the motor is not working at all, you need to replace it.
To remove the fan and motor assembly:

1. Remove the freezer shelf. (If your refrigerator has an
   icemaker, remove the icemaker first).
2. Remove the plastic guide for slides on left side by
   unscrewing phillips head screws.
3. Remove the grille by removing one screw and pulling the
   grille forward.
4. Remove the Fan Motor assembly by loosening 2 screws
   and disassembling the shroud.
5. Pull out the fan and separate the Fan Motor and Bracket.
6. Replace fan motor assembly in reverse order.
   

check you air damper
you should feel air near the top with the freezer door closed
mkae sure your air retrun behind the drawers is clear

These fridges have an evaporator fan motor on both sides - the freezer and fridge side. The freezer can maintain it's temperature because that fan is working fine. I had the same problem, and replaced the evaporator fan motor on fridge side, and it solved the problem. Also, if your fan motor is not working well, or stops working, the evaporator is prone to ice build up, and will prevent proper cooling. You may want to open up panel on fridge side and see if that's the case. Taking a blow dryer to the evaporator and surrounding area (while fridge is off), or letting it sit for a few hours might solve the problem. Ultimately though, it appears as if these fan motors are prone to failure, and need to be replaced.

ok what he was trying to say is that the freezer does all the cooling for both sides as nothing in the fride side cools and in order for the fridge to reach its proper temp the freezer should run any where between -0 to-10 then the fan in the freezer draw-es air from the fridge and cools it and circulates to the fridge now i need to know a few things is the compressor running is the freezer fan running do you see any frost on the back wall of the freezer section is the fan running in the back that's near the compressor to cool the condenser coils then i can better advise pleas hold my rating till we are done where did you purchase the unit

if fridge freezer sits down after power outage on a rs21dcns where interior lights are lighting but nothing else is working press power freeze and power cool buttons together for a few seconds should repower unit

Sounds like the circ. fan may be hitting something or has a blade broken off. The refer gets cool air from the freezer section to cool it so the fan aids in the circulation along with vents/dampers, etc. to move air into the refer compartment. If that fan is broken off the motor shaft or something then the motor can run but no air will move. See if you can feel air moving out of the vents, it will be a little bit of "blowing" not a huge wind. A wet hand can help feel for wind. I believe the deodor light may indicate a change is needed (but check the owners manual for actual meaning). If there is no air flow open the freezer section and see if the air flow is noticed then... if a air channel if frozen and can't draw air from the proper area, opening the freezer door will give it outside air and you may feel flow then, that would tell you of a frozen air channel issue.