MICROWAVE NOT HEATING AND TURNTABLE NOT WORKING BUT EVERYTHING ELSE DOES. WHAT IS THE CAUSE OF THIS?

The problem is more than likely a bad door switch, a digital meter is the best option for testing to find the defective one. If you have one post back for instructions or have serviceman repair it.

There are three common causes, magnetron, cracked high voltage diode, and a high voltage capacitor,"sometimes shorts"

There is nothing more you can do, you have verified everything is working except it is not heating the food. The next step is have the repairman come in to isolate the cause.

Magnetron and accompanying high voltage diode are usually to blame. Everything else works but the magnetron isn't resonating (providing the proper energy to excite your water molecules).
An appliance repairman can change it for you (typically $180) or you can get a new microwave.

If everything is working normally, except for heating, the likely cause is the magnetron.  Microwaves can be dangerous to work on, as the site below points out.  If you have an ohmmeter, it is possible to check the magnetron, but be certain to follow the precautions outlined at the webpage:
http://www.gallawa.com/microtech/mag_test.html

Generally the magnetron (the part that heats the food) is the cause if everything else still works. Unfortunately replacing the magnetron is barely cheaper than buying a new microwave though you can check out repairclinic.com to decide whether you want to attempt replacing the part.

Let me know how this works out for you.
Benjamin

Most likely you have a magnetron problem. Easy to replace (DYI) but make sure the high voltage capacitor is fully discharged first against the case.

The fact that the microwave and convection both do not heat indicated that the oven is in demo mode, check the user manual, otherwise it will possibly be a relay not triggering, may need a pcb replacement, check Demo mode 1st....Phil

Does the turntable rotate? If everything but this works (except no heat), you probably have a bad door switch. Here's a discussion of what's involved in replacing it: http://www.fixya.com/support/t267796-kenmore_microwave_hood_combination_over

If the turntable does rotate, I'd suspect a more significant failure, such as the transformer, capacitor, or magnetron. If it's any of these, it's time to replace the unit.

check turntable motor or bush, this very easy problem, you can use oven no problem..