Iberna oven ,when i switch on the oven it chips the fuse box out

Probably a faulty door interlock switch.

There are lots of models in the range, but it seems they all have a thermal fuse. See the link and the images tab.

https://www.google.com/search?q=defy+gemini+gourmet+multifunction+thermofan+double+oven+fuse+location

The correct search query would be

make (numerical model) thermal fuse location
..

Check input power supply by tester if its conform its OK then check the oven control box .try to check any abnormalities there .

There are screws to take the cover off, look closely, or find it online.

Be very careful, there is a large capacitor in there that can do you some harm.

If no power fuse behind panel but may be thermal switch behind top vent remove and you can see it 2 black wires the spade may need to be tighten.This is the fire safety thermal. Test for 110 volt across to test.

Inspect the door switches and the wiring in the light bulb circuit. If the problem is a door switch, it will probably be visibly broken, or there will be burn marks on it. It's also possible that the door switch bracket is bent or broken and allows the terminals to short to the oven frame. Check the lamp socket - if it is cracked or burned, it should be replaced.

Also look for signs of arcing or burn marks on the controller board, especially near the relays (usually black plastic boxes about 1" x 1' x 3/4' mounted near the wire terminals or wire harness connector).

As a general note, it is rare for a fuse to fail by itself. If you find a blown fuse, look for a cause before replacing it. This may prevent wasting another fuse.

The main fuse in the microwave has blown, this usually is caused by a defective door switch.

You can try to take the unit down and open the cage. Look at the door safety switches and see if they also popped out of place. She might have permanently damaged the door. But don't panic just try what I just explained. Turn off all power first at the breakers.

Check your door switches or your turntable motor, these could also cause the fuse box to trip.

If your microwave oven doesn't seem to work at all, check these: Fuses Usually, when your microwave oven doesn't work it all, the internal fuse (thermal fuse) is blown. This fuse protects both you and the oven. When it blows, you need to have a qualified appliance repair technician replace it. Door switch If the fuse isn't the problem, check the door hooks and the door-release button. When these are broken, the door switch doesn't activate, so the oven can't work.
thanks