Oven playing up

[stevelondon2021]

Hi all. Having a problem with my double oven. I turned it on today, (it was already on as in the clock was displayed, but as I turned the knob for the oven to come on) there was a spark and killed the fuse and RCD. Turning it all back on proved the oven as dead. Power is getting into the back and up to the main PCB as pictured below.


I have removed the PCB and found scorch marks where something has blown and taken out some other bits. I do know a little bit about electronics and know my way around a soldering iron but only basic need-to-know stuff so was hoping for some help from the experts as I am hoping it is something I can just order online and solder on to replace.

I have attached a photo of the PCB with the issues that I can see (not saying that there isn't more). I have put my multimeter across some of the damaged parts and have tagged the results.


1. I know this is a transistor and it has a pin come off the board and will need replacing. Are these all the same or will it be specific?


2. From searching the S10K275 number printed on it this is a Varistor. This has a long blown from the board.


3. I assume a capacitor of some sort from the 'C' number printed on the PCB next to it. The left and middle one show some resistance when MM put on 2M but the right one doesn't read anything.


4. Jumper wire also blown. Can I replace this with a normal piece of wire or does it have to be something specific?


My questions are, can anyone tell me where they think the problem might have originated? Does the above sound right? If I manage to find and replace the above parts, is it likely to work or do you think these would have blown due to a different problem somewhere else?


Oh, not sure if its worth mentioning, but I took the lamp in the oven out and it has blown. I thought it be a little much if the lamp blew and took out the PCB but I dunno??


Thank you all in advance, any advice or help needed.




Steve

 

[stevelondon2021]

I have just noticed something. On the underside, the pins labeled L3 go to the JP wire thats blown. It then splits off to the blown Varistor, then to the yellow transformer looking thing behind it.



1. Is that a transformer?

2. Is there a way of testing this whilst powered down for faults with a MM?

3. Could it be the yellow thing that has caused the problem and just a few little components?

 

[Alec_t]

Welcome to EP.
I'm guessing a Whirlpool oven?
I agree the yellow thing is a transformer. It looks to have suffered heat damage and may well have caused the failure of the other parts. Unless you know its specification you won't be able to replace it. Since several parts have failed it is likely to be uneconomic to purchase replacements individually. Time for a new pcb .

 

[stevelondon2021]

Welcome to EP.
I'm guessing a Whirlpool oven?
I agree the yellow thing is a transformer. It looks to have suffered heat damage and may well have caused the failure of the other parts. Unless you know its specification you won't be able to replace it. Since several parts have failed it is likely to be uneconomic to purchase replacements individually. Time for a new pcb .

Hi and thanks for your reply.

Yes it is indeed a Whirlpool. However its about 13 years old and cant seem to find a replacement PCB for the model. I figured the components aren't that expensive so worth trying to repair myself.

The only thing on the trany is...
WPLHAL009-00092
LSE 0650F3

But don't think that really screams what it's actually rated at. However there is no burn marks on any of the legs of it.

 

[stevelondon2021]

Welcome to EP.
I'm guessing a Whirlpool oven?
I agree the yellow thing is a transformer. It looks to have suffered heat damage and may well have caused the failure of the other parts. Unless you know its specification you won't be able to replace it. Since several parts have failed it is likely to be uneconomic to purchase replacements individually. Time for a new pcb .

Just found a replacement board for £100. I know its not much, but wondered what the chances are of getting the components and doing it myself. Attached a photo of the board I found zoomed in on the transformer for ID. Whats the chances of finding one of these do you think?

 

[stevelondon2021]

So I refitted the board, wired it up and turned it on and took some readings. The JP jumper wire that broke (number4 on pic) was live with 240V. It appears that is the main feed into the transformer with the primary being on the right side of the pic and the two secondaries on the left. I measured all across the transformer with nothing on any pin. To me (and I may be wrong, in fact I usually am) that the components have blown 'on the way' to the primary.... If the tranny had gone open wouldn't it have killed the components after the secondary outputs which are low voltage? Could it just be that something had blown on the way into the trans? Ie part 1,2 3 or 4 which then took the rest out?

 

[Alec_t]

I measured all across the transformer with nothing on any pin.

Not sure what you mean. Nothing connected to any pin, or no voltage on or between any pins?
If the tranny has a fault I think you're out of luck, as it's got non-standard secondaries.