Help needed identifying a component - AEG Convection Microwave

[guando21]

Hi all,
I have an AEG convection microwave that blew it's plug fuse. I can see a blown component on the main PCB but i'm struggling to identify it. Can anyone help? It had a blue label with some part numbers that was stuck over another label. I have searched for the numbers on both with no luck as yet. Photos are available here:

https://drive.google.com/folderview?...LyaAC4U_8llYbB

Thanks in advance.

[stj]

Re: Help needed identifying a component - AEG Convection Microwave

that's a transformer, why do you think it's bad?

if you replace the plug fuse, what resistance do you meter between the live and negative?

btw, dont use google - it's a pin in the ass.
upload pics here.

[redwire]

Re: Help needed identifying a component - AEG Convection Microwave

I see a 12V SMPS with TOP257 IC. Can't see a fuse, is it for this section or the magnetron, the one that is blowing?
That's the SMP transformer, which is custom part for the oven. They don't fail and the housing crack looks to be the potting compound.

[R_J]

Re: Help needed identifying a component - AEG Convection Microwave

The main fuse is usually a high current fuse, It could be blowing because of a faulty door switch, If the monitor switch is bad (contacts shorted) as soon as the main door switch closes the fuse will blow. It could also blow due too too much load, either a shorted high voltage capacitor, high voltage diode, shorted magnatron or high voltage transformer

[guando21]

Re: Help needed identifying a component - AEG Convection Microwave

Thanks for the replies...a bit more info might be helpful. The model number is AEG MCC3885E-m. A friend asked me to look at this after she called out a 'repairman' who replaced the 13amp plug fuse and switched it on. They said they heard an electrical crackling sound coming from the front left corner of the front panel. The repairman said he didn't have a torx screwdriver so couldn't remove the top cover and left it at that after charging £72 for his efforts

Anyway...the component in the photos has a crack across the top of the casing and is located in the area where the crackle was heard so I assumed that was it. I haven't done any further investigation as yet but I will check what as suggested and report back.

I usually work on larger stuff like white goods etc, I'm only doing this as a favour so any help would be appreciated.

[guando21]

Re: Help needed identifying a component - AEG Convection Microwave

Pics here

[R_J]

Re: Help needed identifying a component - AEG Convection Microwave

That appears to be the low voltage smps transformer for the control panel. If the unit did not blow the fuse when it was first plugged in, I don't think that is the problem, although cracked from heat it may not be the issue. If it was indeed bad, as in shorted I suspect the switching ic next to it would have left the board.

[CapLeaker]

Re: Help needed identifying a component - AEG Convection Microwave

for £72 you can buy a new microwave! Gee!

[R_J]

Re: Help needed identifying a component - AEG Convection Microwave

It is a combination CONVECTION, Microwave oven, they are usually quite a bit more .

[stj]

Re: Help needed identifying a component - AEG Convection Microwave

diode gone wild did a good eductational video recently.
https://www.youtube.com/watch?v=BNW7FnEKa7Y

[guando21]

Re: Help needed identifying a component - AEG Convection Microwave

for £72 you can buy a new microwave! Gee!

This thing cost nearly £500 and matches other built-in appliances in a set. Plus it's owned by an OCD person with special needs. My first response was to tell them to replace it but it's no longer available new and the current model doesn't match the others.

[guando21]

Re: Help needed identifying a component - AEG Convection Microwave

Thanks for the other replies, I will have another look at it today and report back.

Cheers

[R_J]

Re: Help needed identifying a component - AEG Convection Microwave

If you replace the fuse, then plug it into the outlet and the display comes on, that transformer is ok. I would then try the convection part of the oven, if that is ok, the fault would be with the microwave section of the oven.

[guando21]

Re: Help needed identifying a component - AEG Convection Microwave

Just to follow up... replaced the fuse and plugged it into an RCD for about 5-10 seconds. Had a low continuous crackling sound and the display panel flickered on and off for a few seconds and then stayed off. Also did a few other checks and I think the convection element was short. The device has now been returned to the owner and I recommended they buy a new one. Many thanks for the help.