How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site.
    Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask Michael Your Own Question
Michael
Michael, Customer Service
Category: Appliance
Satisfied Customers: 9565
Experience:  I have been an appliance repair tech for over 30 years and will help you solve your problems.
11519491
Type Your Appliance Question Here...
Michael is online now

Zanussi zmc30stq fuse blows when microwaving. Oven & grill

Customer Question

Zanussi zmc30stq fuse blows when microwaving. Oven & grill OK. Any ideas?
Submitted: 2 years ago.
Category: Appliance
Expert:  Michael replied 2 years ago.
Hi and thank you for choosing Just Answer.
I am Tech Michael and I will be assisting you today.
Please be patient as these are technical questions that may require a bit of conversation to solve. Also remember to be detailed in your description of the problem. That will help me make a diagnosis quickly for you.
When exactly does the fuse blow while using the microwave oven?
Also which fuse blows, an internal one and its location, or your home fuse panel fuse?
And how old is your microwave oven.
I know this is a lot of questions but I will need answers to each one to help you correctly, please be patient and answer these as best you can so I can assist you quickly;-)
Thank you
Tech Michael
Customer: replied 2 years ago.

The fuse is the internal 8Amp slow blow, where the mains cable enters the oven.

It blows about 2 seconds after starting to microwave.

The convector oven and grill work OK (providing that the micowave hasn't blown the fuse first).

THe oven is about 5yrs old but I use it in my holiday home in Spain so it is only used for 15 weeks or so per year.

I am currently in Spain until the end of the month.

Expert:  Michael replied 2 years ago.
Thanks Alan,
This is one of two things, either the magnetron (heating device) has shorted out or its accompanying transformer has failed.
Usually it is the magnetron at fault.
Its pretty easy to replace if you are a bit handy and have a few basic hand tools, I can assist you as well at no extra cost to you;-)
A word of caution is in order here, microwave ovens can contain lethal voltages even when disconnected from their power supply!!!
There is a capacitor inside that you need to stay away from it is located near the cooling fan and it is a large round can shape usually aluminum.
If you aren't comfortable worming near high voltages then you are best to have an appliance repair technician do this repair for you.
But if you stay away from the connections to the capacitor you will be fine. Also the part can be safely discharged with a well insulated screwdriver and some further advice from me when you are ready to replace the magnetron.
The best place to get a new magnetron is Espares: 0844 9777 888.
It is best to call them for this part. They usually ship the same day and are very good with quality and cost;-)
I will stick with you until your unit is working correctly, You can always get in touch with me if you need further assistance after rating.
Please rate my service kindly thus far, and thank you!
It is the only way I receive credit for my time with you;-)
It won't cost you anything additional to rate;-)
Have a great day Alan!
Thank you!
Tech Michael
Customer: replied 2 years ago.

Thanks for that. Is there any easy way to identify if the transformer is at fault? Also can I put this conversation on hold until I return to the UK as it will be easier to fix when I am at home. I am quit happy with HV as i was a TV transmitter engineer until my retirement.

Expert:  Michael replied 2 years ago.
Sounds good Alan,
Yes, disconnect the magnetron form the transformer by unplugging the wires, then run the micro, if it still blows then the problem would be the transformer;-)
And to put your conversation on hold with me please rate my service kindly, then I will make a note of that and keep you and I active so you can reply to me whenever you need me, at no additional coat to you;-)
Please rate kindly at this time and have a wonderful day Alan.
Customer: replied 2 years ago.

If I leave the wires diconnected, will it be safe to use the oven and grill untill I can get the neccessary spares?

Expert:  Michael replied 2 years ago.
Hi yes that will be fine;-)
Michael, Customer Service
Category: Appliance
Satisfied Customers: 9565
Experience: I have been an appliance repair tech for over 30 years and will help you solve your problems.
Michael and other Appliance Specialists are ready to help you
Customer: replied 2 years ago.

Sorry it's been a while but I am back in the UK and have replaced the magnetron. The same problem exists! Every thing else works if I remove the lead to the thermal cutout on top of the magnetron. I would have thought that this would mean the magnetron was at fault. Any other ideas?

Just a thought, should I have disconnected the 2 leads at the bottom of the magnetron? Also would a faulty capacitor show the same effect? I ask because there was no discharge when I shorted it out.

Customer: replied 2 years ago.

Not sure if you got he last reply as it says Finished.



Sorry it's been a while but I am back in the UK and have replaced the magnetron. The same problem exists! Every thing else works if I remove the lead to the thermal cutout on top of the magnetron. I would have thought that this would mean the magnetron was at fault. Any other ideas?

Just a thought, should I have disconnected the 2 leads at the bottom of the magnetron? Also would a faulty capacitor show the same effect? I ask because there was no discharge when I shorted it out.


Customer: replied 2 years ago.
Relist: Other.
Unable to contact Michael to follow up the original answer
Expert:  Dales-Electronic replied 2 years ago.
Hello My name is Ian ~ I am not on the site constantly so please be patient whilst waiting for responses to you queries ~ I can help you shortly but unfortunately firstly I need to sort out a refund for you on the original question as Michael is no longer on this UK based site he is located in America. Give me a short time to resolve this and then we can take you problem forward ~ Ian
Customer: replied 2 years ago.

Thanks for your reply. I'll wait untill I hear from you

Expert:  Dales-Electronic replied 2 years ago.
I've just sent a message to the Moderator of the site asking him to sort it out for you, will keep my eye on it and come back to you later when its resolved. Do you have access to a multimeter?. Second question, did you replace the cut-out when you replaced the magnetron?
Customer: replied 2 years ago.

Yes to a multimeter.

No the thermal cutout shows continuity so not replaced

Expert:  Dales-Electronic replied 2 years ago.

OK good, if you measure the resistance between the two terminals of the magnetron filament what resistance in ohms do you get?

Follow that with resistance readings from one side of the filament to the case what resistance do you get there?

Customer: replied 2 years ago.

0.4 ohms on 200ohm range. Infinity to case 200Meg range

Expert:  Dales-Electronic replied 2 years ago.
.
Customer: replied 2 years ago.

The answer was blank. Could you send it again please?

Expert:  Dales-Electronic replied 2 years ago.
The moderator has advised that you have been given a refund so you will have to resubmit the question again ~ hopefully if you ask for me we can progress the fault finding without starting again ~ Ian
Customer: replied 2 years ago.

Ok I'll do that. Do I need to send all the thread so far or just the original question?

Expert:  Dales-Electronic replied 2 years ago.
No just address the call to me and I'll pick it up