WHERE CAN I GET A REPLACEMENT

Open the cover n you will see the bulb open it by turning it sideways

That exact model number is not showing up, so you may want to check the tag on or in the unit and look here for parts.
Most of the models in this class of ovens were not really made to be serviced, so GE only makes the turntable parts available.
It also sounds like your bulb is an assembly - the socket and bulb and one piece.
So your local appliance parts store should have a generic replacement for it. You should take the bulb.
Be careful when disconnecting the leads.

sTEVE, THE CAPACITORS HOLD A CHARGE EVEN AFTER THE SYSTEM IS UNPLUGGED. A good rule of thumb would be to allow at least 48 hours for the capacitors to discharge before even getting nea them. Then, yes, you can replace the bulb. Thanks

That would be part number WB02X4235 (with a zero in it, not an oh) and you can order it here.

No if the fan works the fuse is fine; unplug and, check the bulb socket

Here you go bud. Just copy the web address below and paste in the address box above:

http://www.partstore.com/ModelSearch.aspx?utm_source=GE-v01-G-01&utm_medium=website&utm_campaign=Brand_landing_pages&s=google&MfgName=General+Electric&BrandName=General+Electric&ModelNumber=JVM1440

Unplug the microwave and try using a small pick to pull on the tab inside the socket a bit. Sometimes a replacement bulb like that is just a tiny bit shorter and will not make contact. Again, MAKE SURE IT IS UNPLUGGED FIRST!

1) unplug unit and remove microwave cover (phillips on 3 sides)
2) unscrew white funnel shaped plastic part near back of control panel
3) remove specialty bulb and disconnect leads
4) look for T170 bulb replacement (eBay has them) or roll your own 25W bulb solution

You are describing the little bulb in the front. The speedcook light is a different bulb

See: http://www.instructables.com/id/GE-Advantium-Microwave-Halogen-Lightbulb-Replaceme/