oven control board - melted wire connection

[zorgoth]

I'm trying to troubleshoot a control board failure. You can see in the picture the board, where a connection was burned and melted some of the plastic. The orange wire there connects to the oven heating element. I checked the heating element and there's still continuity. The stove top, clock, convection fan all still work. I have no problem replacing the control board myself, but i've got a couple questions before i do.

Anyone know the likely cause of this? If it's more than just the control board, i'm not sure i would repair it so i wanted to see if there are other things i should check.

Do i need the white plastic part around the wires, or can i just cut it and put new connections on? Only the left and right posts are connected to wires, so there's space in between. Should i put tape over them after i attach the wire? Otherwise, i'm not sure where to get the plastic wire holder and frigidaire only sells full wire harnesses but i can't even find this one on their site.

 

[Alec_t]

Welcome to EP!

Anyone know the likely cause of this?

I would guess a defective crimp of the connector terminal to the wire resulted in poor contact and hence heating of the terminal.
The burnt section of board could pose a problem if it has carbonised and become conductive. You would have to remove any carbonised part, find a way of connecting the wire reliably to the appropriate circuit node beyond the burnt section, and provide mechanical support, in lieu of the plastic part, for the new joint.

 

[zorgoth]

It's a 13 year old oven. I was cooking at 550F, which i do a few times a month, so i guess it was having a lot of current run through it. But do you think a weaker crimp connection would take 13 years to fail like that?

 

[Bluejets]

so i guess it was having a lot of current run through it.

13 years....think youself lucky.
No more current than usual, just the time it was on.
Trying to heat treat bearings are we...??.....

Burning out is a common failure in spade terminals like this as Alec says.
Don't connect back via any board connector.
Turn the board over and solder orange wire direct to where the burnt out track leads to ( bottom terminal of the relay)
Not much else you can do short of a new board.

 

[zorgoth]

Thanks. I'll pull the control board out and make sure there's no obvious damage on the other side and see where i can make a new connection.

 

[Bluejets]

Thanks. I'll pull the control board out and make sure there's no obvious damage on the other side and see where i can make a new connection.

Looking at the top, I'm sure it'll be bad underneath as well.

 

[zorgoth]

I ended up buying a new control board. the relay looked burnt on the side and although that could be replaced, i'm not confident enough to work on the board components. Question now is on connecting the quick disconnect terminals. Originally there were two embedded in the white plastic piece that burned. Did the white plastic part serve any purpose besides just holding the two wires and their connectors together? I cut the wire off and got appropriately sized terminals. They're just crimp on. Should i get fully insulated instead? Is there a better or worse way to use them? Or a better or worse version of them? Do i need to use additional support in any way?

 

[Bluejets]

The reason fopr the insulation is that they are mains level voltages.
Using a separate insulated terminal would be fine.
If you have already fitted something else, wrap it in some insulation tape.