LG lre3012st electric oven not reaching temp

Oven/Range/Cooktop Repair
1

Please make sure to click on General above and select the correct appliance type first.

**Brand: LG
Model Number: LG lre3012st
Main Symptom: not reaching temp.
What happens & when:
Set oven to some temp, 400, 450 . Doesn’t seem to matter.

Oven will reach a low temp per external thermometer. ~255 or ~355. But never to desired temp. Sometimes will hold this temp sometimes starts dropping

Broil seems to work fine

Error Code (if any): none
Parts or tests already tried:
Tested broiler elem and heating element. Both have continuity and seem to heat up.

Temp sensor had correct resistance. Replaced it anyways. No fix.

What is next step? Thank you!

Photos / video link:

2

You would replace the oven control board located in the console. Make sure to check the heating elements for resistance, not continuity. Most heating elements will read about 20 ohms.

3

As far as I can tell there is the main control board and the relay board.

How can I tell which one is bad?

4

You are looking for the board that controls the oven, it will have relays that open and close to turn the heating elements on and off. The control part number I see is 6871W1N002G, it shows it NLA