LG oven not heating - electrical issue?

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  #1  
Old 09-19-16, 07:54 AM
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LG oven not heating - electrical issue?

Our oven was heating inconsistently at best. Typically it would start to heat up slowly and then stall. We could not get it to to heat anywhere above 300ish and even then it took forever to get there. All other oven functions work fine (range top, oven convection fan, etc.).

1. I did some basic continuity testing for both the bake heating element and the broil heating element. Both of them seemed fine after some basic testing.
2. I then attempted to test the Oven Relay Board and thought I had found the problem. I then ordered an exact replacement.
3. I re-installed the replacement exactly the same as the original (re-attached and attached wires one at a time).
4. Turned on the oven and now I'm getting NO heat at all. The oven seems to have power, all wires seem intact, burners still have continuity.

What am I missing to troubleshoot next? How can I be sure the relay board I ordered is good? How can I test this board to rule it out as a problem. I guess I'm not really sure how to test this board for continuity itself.

Thoughts?
Thanks.
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  #2  
Old 09-19-16, 09:31 AM
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If you look at the bake terminal on that board you can see it's gotten hot. That usually signifies a poor connection. Can you post a picture of the back of the board. Try to make it a little larger than your front picture.

Did you confirm 240v coming in the range ?

Can you post another pic of just the bottom corner too ?
You are missing a grommet or clamp on the power cable where it passes thru the chassis.

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Old 09-19-16, 10:04 AM
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Thanks for helping.

Here is a picture of back of the old board. Some slight discoloration there also I think. Also attached a portion of that original picture slightly zoomed in (I can take a better picture once I'm home later today).

I believe I'm getting the right power to the stove overall because the range works fine and a simple test shows power running to the wires (just with my analogue tester).

Note: I have a brand new board that I re-installed and as mentioned above now that I've installed the new board I don't seem to be getting any heating response at all.Name:  Back of oven board.jpg
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Old 09-19-16, 03:12 PM
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Some of those connections look bad. However, that doesn't explain why the new board is not working. When you turn the over on do your hear a click from that board ?

Can you post the model number so I can locate a wiring diagram.

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Old 09-19-16, 08:32 PM
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Thanks again. A few things...
1. Attached pics of old and new board. Any way to test the new one is actually good?
2. When I tip the old one over I hear a small sound of something moving inside. I almost feel I hear the same thing on the new board but definitely quieter. Mean anything?
3. Oven model # LRE30453ST /01
4. I did test and power is reaching the board (simple volt test)
5. When I turn the oven on to either bake or broil the digital display just sits at 100 but the oven never heats at all. Should I expect to get power at the heating element terminal itself (no power when I test there when the bake oven is turned on)?

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Old 09-19-16, 08:51 PM
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Appreciate the pictures but I can't use them. The board compresses them and I can't read them.

I can't read the model number either.
There may be a publication number on the tech sheet that I can use.
 
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Old 09-20-16, 08:38 AM
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Are you asking about the oven model number? I had included that in my post below. Here it is: Oven model # LRE30453ST /01
 
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Old 09-21-16, 06:38 AM
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Any additional assistance or input? Somewhat stumped here. Just wondering if there are other things I should test.
 
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Old 09-21-16, 09:48 AM
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I didn't see the model number previously posted.

I've located the service manual for your range. I'll check further into it tonight.

appliance factory parts/content/pdfs/142555-2.pdf
 
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Old 09-21-16, 11:16 AM
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No problem. Thanks for the link. Walked through the troubleshooting flow. Everything seems good except possibly the oven sensor. I'm not an electrical expert but on my analogue multi-meter tester it seems the Ohms are reading higher than the normal reading.
The manual says...
Normal: Approximately
1.09 kΩ 10%

My test if I'm doing it right shows more like 9kΩ

Thoughts on that? Is it possible that a bad sensor would prevent the oven from heating at all, impacting both the broil and bake elements?

Otherwise, I'm at a loss unless the new oven relay board I purchased is also bad? I doubt this is the case but it almost feels like it is considering I get zero heat response when turning bake/broil on.
 
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Old 09-21-16, 11:40 AM
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So, still playing around with it. Something interesting. I put the old oven relay board back in. Still no heat response for bake/broil HOWEVER I do here the oven relay board click fairly loudly when I first turn bake on, and then I hear it click periodically. Sounds like it typically did and sounds like it's trying to work. When I put the new board on I hear no clicking. From vague recollection when the oven is working correctly I do hear that clicking. Feel like I'm going in circles here and hoping the new board I bought works. Symptoms seem to suggest that new board isn't good. Any way to directly and easily test that board?
 
  #12  
Old 10-12-16, 04:32 PM
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I'm still troubleshooting this and I guess it's about time to call the repairman. Bummer. I have the new relay board in place and it seems to be working from what I can observe. All elements are in good shape. But when I turn on bake/broil I simply get no heating response. So confusing. Any last input or troubleshooting recommendations?
 
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Old 10-12-16, 04:38 PM
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I'm on the road and will check back in later tonight.
 
  #14  
Old 10-12-16, 04:44 PM
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Thanks. If I follow the failure flow in the manual it seems to bring me to the primary board as the last resort step... but I'd hate to just replace that unless I can get some certainty that is the problem. Seems strange to me.
 
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Old 10-12-16, 04:47 PM
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If the relay board is clicking... then the control board should be ok.
 
  #16  
Old 10-12-16, 05:17 PM
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Exactly what I'm thinking. It is clicking as it normally would, sounds fine, etc. Heating elements are fine. Feel like I'm missing something obvious but at this point I have no idea what it could be.
 
 

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