FIXED 790.72702012 Kenmore Oven Control Board no power

GameEngineer

Premium Member
Joined
Oct 15, 2012
Messages
4
Location
San Diego, CA
Model Number
790.72702012
Brand
Sears Kenmore
Age
6-10 years
The oven is a Kenmore gas range/oven (model: 790.72702012) purchased new in 2012 from Sears with a control board P/N 316418501. Recently I turned on the oven to start heating and in about a minute or two I heard a loud pop and the power on the control panel was off. There was no oven heating either obviously. After checking the outlet, breaker, etc there was power on the outlet and using my voltmeter there was 120 VAC on the main connector that goes to the back of the control board. The oven wiring diagram showed pins 4 and 5 on the connector that goes to the control board had 120 volts yet the board was dark. I removed the control board and smelled that familiar burned electrical smell. It seemed like it came from one of the big cube black components (relay?). But there was no discoloration. I even took the circuit board out from the plastic frame and looked on the back side of both circuit boards and still not visible signs of burned traces or components. But its still bad because of the input voltage is there but not power.

The stove ignitors work fine and since its a gas range we can still use the cook top. But the oven is not working because of the damaged control board.

Ok so I ordered a new OEM one but now I am feeling a bit nervous plugging it in when it arrives because the root cause may still be there that caused the board to fail in the first place. So here's the reason for my post. I'm looking at the wiring diagram for the oven that was supplied with it and the only tings I can think of to check are the Temperature probe, door switch, lock switch mdl (mdl?), oven light (which has a good bulb but even then I wouldn't think it would cause a board failure), motor lock and bake and broil ignitors.

Any advice as what I can check? I've checked the main safety gas switch solenoids with an ohm meter and they are fine and like I mentioned the gas range works so I know those switches are working. One last thing I can mention as far as "what changed" recently which may explain why the sudden failure. I had to move the oven out into the garage while we tore the flooring up to get ready for new flooring. I thought I was careful with my dolly moving it out and back in but I wonder if something that inputs into the board has damaged. Not sure what to check other than continuity check on things.

I'm not a service repair guy but I do like doing electronic hobbies so I do know a bit about electricity and I have a decent voltmeter and am not afraid to use it.

The new control board is coming in a week so I have to figure out how to check other things in order to not blow the new part. :sulkiness:

-Steve
 

jeff1

Appliance Tech - Moderator
Staff member
Joined
Oct 10, 2004
Messages
23,800
Location
Ontario, Canada
Hi,

I'm looking at the wiring diagram for the oven that was supplied with it and the only tings I can think of to check are the Temperature probe, door switch, lock switch mdl (mdl?), oven light (which has a good bulb but even then I wouldn't think it would cause a board failure), motor lock and bake and broil ignitors.
Nope.
Nope.
Nope.
Nope.
Nope.
Yes.
Yes.
Just look for continuity and nothing to ground on the ignitors.

jeff.
 

GameEngineer

Premium Member
Joined
Oct 15, 2012
Messages
4
Location
San Diego, CA
haha! Awesome! I love your reply!

I actually found the problem a couple hours ago after getting home. I studied the wiring diagram more during the day and came to the conclusion that the best place to start looking was the igniters. You confirmed my suspicions. I visibly checked the igniters first starting with the bake igniter. I removed the bottom plate and it was obvious! It was completely destroyed! A fork was laying next to it and it looked like it was arc welded. It all makes sense to me now. This fork had somehow gotten under the oven floor plate and when I tilted the oven on the dolly to move it the fork moved into position touching the igniter resistor metal. Once I turned the bake on it sent current to the igniter to heat is up and POP! arc welding since the fork was grounded on the oven floor. The short then caused an over current that made its way back to the control panel and it blew as a result. (side thought) why the heck doesn't the manufacturer put a breaker in the over so at least you don't blow an expensive control panel ($200 or almost $400 if I buy from Sears directly which ain't gonna happen..... ever!!! Same OEM part cheaper other places)

So if I had checked the continuity of the igniter it would have shown on open which would have led me to pull the plates eventually. I just did the visual first.
That was a $280 fork!! 200 for the control board and 80 for the igniter. Thanks for the help!

-Steve
 

jeff1

Appliance Tech - Moderator
Staff member
Joined
Oct 10, 2004
Messages
23,800
Location
Ontario, Canada
Thankx for the update :)

jeff.
 
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