Failure on oven control board

Discussion in 'Electronics Repair' started by Swoop, Jan 5, 2017.

  1. Swoop

    Swoop

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    Hello,

    I am trying to figure out what this shorted/burned blue plastic component is on the control board of a Samsung FE710DRS oven. It is labeled 'KET 6 M6635194' and wired between the terminal block and the heating element. Anyone know what its function is or how to replace it?
    (Images of the replacement board do not include this component)

    Thanks!

    IMG_0024.JPG
     
    Swoop, Jan 5, 2017
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  2. Swoop

    Tha fios agaibh

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    Looks like a terminal block insulator that melted. Likely that black relay behind it failed, causing it to overheat.

    If it was my oven, I'd cut and strip back a few inches of the burned wires and crimp or resolder directly to board after replacing relay and verifying element was ok.
    You can use shrink tubing to insulate terminals instead of the factory connector.
     
    Tha fios agaibh, Jan 5, 2017
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  3. Swoop

    shrtrnd

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    That's a considerable over-heating problem. I wouldn't just replace the relay and wire everything back together.
    It sounds like you've found a replacement board, and assumedly that was the problem; but since this is an oven
    and I don't know where all those interconnect wires go to, I wouldn't bet a possible house-fire on it.
    Isn't this something you should refer to an authorized appliance repairman?
    If you're looking for just the melted blue plastic connector, a Samsung replacement should be available from
    an appliance replacement parts store in your neighborhood (or on-line), and they'd probably be able to recommend
    a repairman for your issue.
    My opinion is it was probably the board you want to replace, and it'll need a new connector. But I'd want to
    have the entire oven checked-out before I powered-it-up again. Might be damage elsewhere.
    That's my two-cents worth.
     
    shrtrnd, Jan 5, 2017
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  4. Swoop

    Alec_t

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    Looks to me (looks can be deceptive) as though the cause could simply have been a bad (loose, poorly crimped?) connection from the red wire to the push-on spade connector inside the blue housing. High current through that relatively high resistance would have resulted in localised over-heating. Chances are the board itself is healthy.
     
    Alec_t, Jan 5, 2017
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  5. Swoop

    Minder

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    I just recently repaired an almost identical board, you need to remove it to see any flash over damage on the reverse side.
    In my case it was a flash over from one foil to the next adjacent to a relay terminal pin, I replaced the relay ($2.50) just in case, and after repair I coated the foil with conformal coating.
    They wanted $200.00 for the board!
    M.
     
    Minder, Jan 5, 2017
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    Tha fios agaibh likes this.
  6. Swoop

    Tha fios agaibh

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    Sage advice to get a qualified repairman but with all these type posts, it's assumed the poster realizes he or she is working with dangerous currents but feels confident in doing the work themselves but are seeking guidance from the community.

    I've seen problems like this hundreds of times. That relay switches high current thousands of times and eventually the contacts get pitted or weak or even weld together.
    This high resistance in the contacts causes over heating which is transferred to the nearby terminal and melting the wires.

    Yes, it's possible that the terminal block was just loose as Alec T suggested, but I'd investigate the relay also.
     
    Tha fios agaibh, Jan 5, 2017
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  7. Swoop

    Swoop

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    Thanks to everyone who replied! I removed some of the charred material and discovered that the board is more damaged than I realized - you can see the hole in the board in the pic. Even if I could find, figure out how to remove, and replace the blue connectors, and then replaced the black relay, I doubt I could make a good connection with this much damage to the board. think this is beyond my skills.

    Samsung recommended a local repair outfit, but I don't want to use them b/c they are poorly reviewed online. For what the repair labor & board will run, I may be better off buying a new oven.... it won't be a Samsung.

    IMG_0025.JPG
     
    Swoop, Jan 6, 2017
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  8. Swoop

    Tha fios agaibh

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    Even if board is melted beyond replacing the terminals, it may be possible to install a relay externally elsewhere in the oven.

    But I respect your decision to call this one a lost cause
     
    Tha fios agaibh, Jan 6, 2017
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