Sparks it is making lots of sparks from the ''dohicky'' on the right hand side inside the oven. Im guessing its the part that makes the microwaves, about the size of a 1/4 roll of nickles.

yes you can but you should not. Take the shielding wall from another similar microwave if possible, the magnetron waves can seep thru the smallest crevasses and will repeatedly cause more damage if not fitted properly, im not so sure what type material is used but more than likely it is non conductive, careful magnetrons are dangerous thats why companies that make microwaves have such strict guidelines and safety measures, there are so many switches to prevent direct exposure to the magnetron, it is so dangerous the goverment developed a weapon from the technology--if your insist on repair please find exact replacement parts- careful and good luck more questions just ask

Look in side and make sure there is no pieces of aluminum foil or metal hidden inside. If not I would not use until you have a appliance repair person look at it.

This is not good, the magnetron is arcing because metal is exposed, this will eventually destroy the magnetron making the oven useless. I strongly suggest it get looked at for safety and potential fire hazard.

Presuming that you have iliminated the possibility of any metal objects that are not meant to be in the machine being in there (and this includes dishes and other items with silver or gold leaf on them, which WILL spark and burn!) then take a look inside the oven its self. You will find a waveguide cover. It is usually a strange flakey silvery plastic/card like material called Mica and is usually on the same side of the microwave wall as the control panel (So if the picture on this thread is accurate, I will guess the Mica cover is on the right hand wall inside as you look at the machine from the front) . Over time, the magnatron (the thing that creates the microwave energy) will often burn a hole through the mika, or cause a dark brown or black burn mark in it. If this cover is even slightly damaged then it may well cause sparking inside the machine. These covers are designed to be removed and you can buy replacements for them from electrical stores.

Usually the sparks are from exposed metal. Clean the oven, and the table and anything else you can inside. Then just try nuking a cup of water. That gives it something to work with and it won;t make any sparks itself. Then just see if the sparks are gone. If the paint has come off inside the cavity and exposed some metal you can get sparks but that usually means replacing the microwave. If its caused by an object or buildup then a good cleaning stops it.

I would certainly take it to a repair shop if you want to try and salvage it. Until then keep it off and unplugged.

The Magnetron has failed, causing the waveguide to become damaged. If the waveguide is damaged/burned the microwave can not be repaired and should be replaced.

It could be a magnetron sparks to the open metal inside the m/w cavity or some broken wire on high voltage side. It is not HV transformer (when burn create a lot of smoke and bad smell). Magnetron needs to be replace.

I’m happy to help further over the phone at https://www.6ya.com/expert/vitaliy_f406165329c75ede

The magnetron tube which makes the microwaves is behind that cover plate, and it has gone bad. It is a replaceable part, but it's not worth the cost. Part and labor would be more than a new oven. It's time to treat yourself to a new oven.

The cover is probably the magenetron. That is where the microwaves come from. If the bread was moist, it might have left condensate in the unit which is causing the sparking. Unplug the unit, leave the door open over night. If you can remove that cover, do so. Be sure to carefully replace it before using the unit. Never turn on a microwave with nothing in it.