Repairs are expensive. New microwaves are cheap. But you don't have to spend a dime on either. If your microwave turntable stopped spinning, here's an easy way to try and fix it. And all you need is some warm, soapy water and your own two hands.

You don't have to be an appliance expert to troubleshoot a seemingly broken microwave turntable. You might find that all your little Zappy needs is a checkup and a good, thorough cleaning.
If you follow these steps and find that your microwave still isn't turning, it probably means the motor has spun it's last spin. Then it's time to retire old Zappy.
- Unplug the microwave. Safety first, kids.
- Remove the glass tray and the circular turntable guide. Wash them both in warm, soapy water to get rid of anything stuck. Pay special attention to the rollers on your turntable guide, making sure they're able to spin freely.
- Clean the internal cavity. Make sure to check your microwave's center cavity to make sure it's free of movement-hindering (and gross) leftover food.
- Check that the drive bushing is working. Make sure that the drive bushing, the plastic mechanism in the bottom of the microwave's interior that the glass tray turns on, isn't worn out or split in two. If it is, you'll need to have it replaced.
- Put it back together. Put the turntable guide back into the circular groove. Place the glass tray turntable over the turntable guide and onto the drive bushing. Adjust until the drive bushing should fits perfectly into the grooves of the glass tray.
- Test it out. Zap a mug of water for a short bit to see if you fixed the problem. Do not run the microwave without anything in it.
(Images: Miele.co.uk, About.com)
MORE MICROWAVE TIPS & TRICKS:

Nomade Express Slee...
What happens if you run it without anything in it? Is it like crossing the streams?
I don't know what crossing the streams means, but magnetrons (the thing inside the microwave making the waves) sends out microwaves, and they have to be absorbed by something. If there isn't anything in the microwave, the magnetron absorbs the waves. The magnetron will/can stop working if you run the microwave without stuff in it. (But apparently there's features in new microwaves to make the microwave cut off before it croaks itself? I'm not exactly sure about this part).
too funny Tara, i thought the same thing :D
Sometimes the turntable motor itself can stop working. I had this happen in my built-in, over-the-range microwave. A new microwave would have been $300+, so I bought a replacement motor on-line for $30 at RepairClinic.com. It was pretty simple to replace. You just need the model number of your microwave and they can find all the parts in your microwave. In my case, the dead motor had a part number on it, which made it even easier.
If you're having this trouble you can always ask for help from an expert at http://www.managemylife.com/mmh/questions.
Just enter your model number with the question and you'll get very specific troubleshooting advice.
lol @Tara
For @alysaaria:
http://www.youtube.com/watch?v=jyaLZHiJJnE