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FIXED LG LRE3021ST/00 Electric Range - Oven Temperature Issue

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Mike_Homeowner

Premium Member
Joined
Jun 27, 2021
Messages
5
Location
27511
Model Number
LRE3021ST/00
Brand
LG
Age
6-10 years
I have a LG LRE3021ST electric range oven that is not heating up to correct temperature when Baking. Scenario: Set the Baking temp (ie 390 F), hit start & the panel shows "preheating w/ 100 F" and then it turns off around a minute or so... never reaches temp (ie 390). It shuts off (I here the beeps and turns offs). Oven is slightly warm, so something did happened but it does not go to temp. Did the same thing when I tried to use the Broil & Self clean settings..

It basically starts and than turns itself off after a minute or so. I checked the following with no issues: Power coming in - ok ; 2 Fuses (3B74133K (5001)); Thermistor EBG61305805; Thermostat 6930W1A003X; Bake heater element (MEE62306405); & Broil heater element (MEE62306504). No issues with those parts.

Not sure how to test the relays on the Range PCB (EBR74164812) if one of those could cause this issue. Visual inspection of board, I don't see any obvious issue. So not sure. So, I was wanting additional clues on what parts to check to diagnose this issue. Has anyone seen this issue on this LG oven model and what was the suspect part? Any suggestions on what other parts to check?
 

Jake

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Hi Mike, So when it shuts off does the control board display goes back to the CLOCK/TIME default or does it stay at 390 in the display?

If it shuts off AND the control board display goes back to the CLOCK/TIME default, then your control board is bad:
lg-pcb-assembly-display-ebr73710103-ap5785742_01_l.jpg


Jake
 

Mike_Homeowner

Premium Member
Joined
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Messages
5
Location
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Jake, strange thing occurred. I wanted to make sure I got the exact sequence of events that are occurring before I replied to you, so I went & re-plugged the oven back in (this is the first time since I have been checking all the suspect parts) and did the original sequence of events to start the 'Bake' process. So I hit 'Bake' button, plugged the number in 3,9,0 and hit 'Start'. And what occurred previously was that the display indicated that it was 'preheating' but looking at the temp display it never moved off of 100F and then eventually turned off but was warm inside (probably at 100F). HOWEVER, this time I did the above sequence and the display came off the 100F and started incrementing 5 degrees until it hit the 390F (display seemed fine). So when it hit 390F temp it beeped (as normal) and the temperature in the oven felt like it is at 390F. So to my surprise the oven was working. BUT, when I was going to reply to you we heard the oven beep and to my surprise it turned off. So it was very hot but can't tell you if it was at 390 F or above this temp. And why it did what it did, is racking my brain. I have pictures of before (image 1), at 390F (image 2) and then after several minutes (while writing this reply) the thing turned off (???) (image 3).
So, I decided to let the oven cool down and then did the same sequence above but did it at 260 F (image 4) and heard two clicks and then two ring/bell sounds (in succession) and it then turned off (image 5). Never reached temperature. Didn't feel like it was at 260F . So just to make sure I did this again at 360 F and same thing 100 F displayed at first and then beeped (images 6 & 7) . Never reached 360 temp. So, not sure if my above description helps and changes your mind to replace the control board display you mentioned or if it is something else you think I need to check or replace. Welcome your thoughts.
 

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Jake

Appliance Tech - Admin
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Ok Mike, so it looks like when it shuts off the temperature you had it set at is gone, so its going back to just the clock default, so that usually indicates that control board is the culprit.

So it looks like you will need the new control board I posted the link to in post #2 above.

Now if the temperature was STAYING in place in the DISPLAY and not heating up properly, then the relay board would be the problem, you see what I mean?

Jake
 

Jake

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Ok Mike, sounds good, yes keep us posted.

Jake
 

Mike_Homeowner

Premium Member
Joined
Jun 27, 2021
Messages
5
Location
27511
Had a chance to remove the card (EBR73710103) that you mentioned above and looking on the other side you can definitely see this card is damaged. You can see the pics below that two areas are damaged (image 8; two areas circled in red). One spot the trace was to bare copper (which I didn't expect & maybe a quality issue with the mfg process of this particular card) with what looks like burnt / corrosion. And the other area the trace is blackened / fried (image 9). So yup this is my issue. So, in the process of ordering a new part as you mentioned above . Did see some dead bugs when I removed from the backside, not sure if this would cause the corrosion of the trace, ect..ect. jury is out on this one. But, anyway will wait for the new part and let you know. Thanks for your help! You nailed it.
 

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Jake

Appliance Tech - Admin
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Yes Mike, I clearly see the control board is damaged. I don't know if bugs did that or not either.

But we know for sure the new control board will fix your range after you install it when it arrives.:)

Let us know how it goes.

Jake
 

Jake

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Excellent Mike, glad to hear the new control board fixed it.(y)

Thanks for the update!

Jake
 
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