I have a GE oven model JSP28GOT1BB, the stove works but the oven does not. The timer and clock both work but when I push the bake, broil or clean button I don't hear a beep and the clock blinks off and back on. I tested the power and I have 240 at the plug.

Most likely you have a loose wire in the stove somewhere, and you probably also have loose wires in your wall plug and in the breaker box. First, open your breaker box and use a round-shafted, insulated Klein screwdriver the maximum size for each screw you will tighten and tighten every screw in the box. Then turn off the breaker to the stove and remove the cover to the wall plug and tighten those screws well. Remove the access covers on the stove and tighten all of the screws and if any are corroded take them off and polish with fine sandpaper. Then turn on the power and see if the oven works. If not, you may have a bad switch and you will need to check it with an ohm meter. Do not trust the 240 volt reading you are getting at the plug because that's under no load and if the wires are barely touching it will still read 240 volts. Here are booklets: https://dl.dropboxusercontent.com/u/8010163/How%20to%20use%20Test%20Equipment%20Service%20Manu al.pdf
https://dl.dropboxusercontent.com/u/8010163/GE%2024%20inch%20Self%20Cleaning%20Range%20Service %20Manual.pdf
https://dl.dropboxusercontent.com/u/8010163/GE_Advantium_Oven.pdf