Oven appears to operate normally but doe not produce any heat what so ever.

There are three microswitches
When checking a microwave oven that seems to operate properly yet does not heat first check for 110VAC at the primary of the large transformer.

follow this test and fix it. God bless you

1. Check the power diode This electronic component is responsible for transmitting current in one direction. If the diode becomes defective it will cause your microwave to not heat. Test the diode and replace it if necessary.
   
2. High voltage capacitor Responsible for storing electricity, this part is a key component in any microwave. Remove, discharge, and test the capacitor to determine if it requires replacement.
   
3. Damaged magnetron Responsible for generating waves and producing heat. When your microwave is no longer heating properly, replacement will be required.
   
4. Thermal Cutoffs Examine the thermal cutoffs on both the magnetron and the oven itself. Take off one of the leads and using a volt-ohm meter on RX1, check the terminals. If you get a result other than zero, replace the thermal cutoffs.
   

Hi,
Here is a tip that will help you to figure out what is wrong with your Microwave Oven....

Microwave Oven Basic Troubleshooting Tips
http://www.fixya.com/support/r5508031-microwave_oven_basic_troubleshooting

heatman101

Hi,
Here is a tip that will help you to figure out what is wrong with your Microwave Oven....

Microwave Oven Basic Troubleshooting Tips
http://www.fixya.com/support/r5508031-microwave_oven_basic_troubleshooting

heatman101

Micro wave as the name suggests produces heat when the micro waves aimed at an object causes the water molecules inside the object to vibrate hence producing heat.The gadget responsible is the magnetron. If your magnetron is not receiving ht voltage or receiving but faulty, then your micro wave wont work please take precaution when opening micro wave due to high voltage caps that remain charged sometimes even when it is off.check the high voltage fuse/ diode and capacitor if they are fine and the step up trans former o.k then the only option is to replace the magnetron

all microwaves have a magenetron which produces the heat. if this is gone and it is not under warranty, it is not cost effective to repair. check you manual, most mag's have a 3 - 5 year warranty.

The most common problem spot when the microwave will not heat is the magnetron. this is a device that produces the heating effect. you will need to replace this failed component. it has failed. Replace the Magnetron.

Deart Customer

please undergo the following

Since 30 to 50 percent of the power into a microwave oven is dissipated as heat in the Magnetron, cooling is extremely important. Always inspect the cooling fan/motor for dust and dirt and lubricate if necessary. A couple of drops of electric motor oil or 3-in-One will go a long way. If there are any belts, inspect for deterioration and replace if necessary.
An oven that shuts off after a few minutes of operation could have a cooling problem, a defective overtemperature thermostat, a bad magnetron, or is being operated from very high AC line voltage increasing power to the oven. One interesting note: Since 30 to 50 percent of the power goes out the vents in the back as heat, a microwave oven is really only more efficient than conventional means such as a stovetop or gas or electric oven for heating small quantities of anything. With a normal oven or stovetop, wasted energy goes into heating the pot or oven, the air, and so on. However, this is relatively independent of the quantity of food and may be considered to be a fixed overhead. Therefore, there is a crossover point beyond which it is more efficient to use conventional heat than high tech microwaves

i think the information would help u if so rate me please,otherwise just give it as fixya,Thank u

ya this is the same problem i too had...everything will seem to right but the part required for heating might be damaged internally...try changing tat...here i did the same...

see for the turn table obstacle of any screw or something else.