Microwave keeps blowing internal fuse

Hi Guys.
So i have a sainsburies microwave. One of those premium ones that do defrost etc. It even has a colour screen.


Anyways, so a while ago the Mrs went to put something in to heat and it switched off when she closed the door.

Symptoms: Every time we close the door the internal fuse blows and trips the sockets fuse on the main board.

Checks:
I got her to swap the main fuse - No joy.
I opened the microwave and noticed the internal fuse on the main power board had blown. I swapped it. The microwave came on and blew again when she put something in again.

Tests
I tested all the door switches and when not connected are absolutely fine. When connected they are leaking some where, show a resistance.
I tested the main capacitor with a multi meter and it doesn't show any continuity.
I tested the Main transformer, checked the secondary coil and there is a resistance of 172 ohms.
I tested the diode and there is no continuity in either direction - i presume blown.

Question:
So, if the diode is blown, will it cause the internal fuse to blow when ever the door is closed?

As it happens, I have replaced the microwave with a Samsung one as the Sainsburies one happened to be just over a year old - so out of warranty.

At least if i can fix it i can sell it or give it away so it doesn't end on the heap!

The door has two plastic latches. Are they in perfect order?
If one is chipped and the other is perfect then this can cause an internal fuse to go.

RichardMNZ said:

The door has two plastic latches. Are they in perfect order?
If one is chipped and the other is perfect then this can cause an internal fuse to go.

Click to expand...

Hey.
Thanks for the reply.
This is the first thing I checked. They are in perfect condition. I even checked there activating the switches correctly. Which they are

So I gave up on it. Anyone want it for repairs?

Would be an awful shame to add it to a landfill

Take it to your local recycling centre

Shame you bought a new one. I’ve got replacements on lots of faulty electrical gear out of warranty. Especially big companies who are more keen to avoid bad reviews.... their one year warranty in my book is just to camouflage the fact that goods have to be fit for purpose. I’d argue that a microwave is meant to last over a year thus must not be fit for purpose. But hey, I’m sure it didn’t bankrupt you.