LG oven turning off and flashing "PF"
Well, it is either a whole house power problem or something specific to the range.

Incandescent lights won't show a quick power flicker, but LEDs will.  Look carefully if you know when the range might "PF".

As for the range, it could be internal or it could be the range circuit.  It is worth (since it is a very low cost experiment) shutting off the circuit breaker and turning it back on.  There is like a 20% chance this might fix the problem if the breaker is marginal or the range needed an external power reset.

If the problem persists, do these steps from easiest to hardest:


Slide the range out from wall, (with breaker off) pull out plug from socket and reinsert.  If anything is loose or wonky, tighten or replace.
Open breaker box, shut off range breaker and tighten the wire connectors.  Especially the ground and neutral wires.  Inspect the wire near the connectors:  if any wire is not bright and shiny, cut it off, strip, and reinstall.
With the range pulled out and unplugged, inspect the "pigtail" (cord) connection inside the range.  Tighten screws and look for signs of overheating and sparking.  A replacement pigtail goes for $12&ndash;25.
Open the top where the control board is.  Inspect for melting, soot, smoke, loose connections, etc.  If all other causes are eliminated, it is probably a controller fault.