The wave-guide opening, located in the cooking area
of the microwave is where microwaves transmitted from the magnetron
enter the cavity. In most microwave ovens, the opening of the wave-guide
into the cooking cavity is covered by a part called simply enough, the
“wave guide cover”. This part is usually made from either
mica or plastic, and serves to keep grease and food particles from entering
the wave-guide and damaging it or the magnetron tube. These materials
use for these covers are transparent to microwaves. In other words,
microwave energy passes through the materials and does not affect them.
Problems can arise if food residue collects on the wave-guide cover.
Every time the microwave is operated, this residue cooks just as any
other food in the microwave would.
Eventually this residue will carbonize and begin to burn. This area
will absorb more microwave energy, and will eventually it will start
producing arcs and put out one heck of a light show! Most of the time,
it looks worse than it really is, but sometimes it can be pretty scary
to someone who just wants a hot cup of coffee.
The wave-guide cover can be replaced if burned or carbonized. If the
paint on the cavity is burned, it can be sanded and painted with a microwave
safe interior paint. (If the arcing has burned a hole through the cavity
wall, the damage is non-repairable and the unit should no longer be
operated.)
If the unit is still arcing after replacement of the wave-guide cover
and painting, there may be damage to the antenna of the magnetron tube.
This is the point where one should consult a qualified service person
to make that determination and repair if possible.
Sometimes, popping sounds are caused by the food being cooked in the
microwave. This is especially true of high fat content foods such as
bacon or ham. Many types of meat will pop and sizzle as they cook. Noises
can also be heard when cooking foods with tight membranes such as potatoes.
If the microwave is making noises that sound like arcing, remove the
food being cooked and put in a small glass of water instead. Turn the
microwave back on and listen carefully. If the microwave seems to be
operating normally and has no arcing or popping sounds, it was most
likely the food item being cooked.
Operating the microwave empty may also cause arcing to occur and can
damage the interior or the magnetron tube. Always have something in
the microwave when in use.
- If the popping noise is electrical or mechanical in sound, or you
see or smell smoke or a burning smell, unplug the unit and contact a
qualified service person.
|
