Microwave does not make any noise, but timer counts down

check the supply of element first is it ok check element

There should be a button labeled timer. Hit that then enter the time you want it to count down to. Then hit the timer button again.

There are door switches and one of them is evidently out of adjustment or the little actuator arm on it is.

either the magnatron fried , or the fuse fried... either way the microwve has to be taken down and opened up.
If you have the serial number , GE will send you a replacement magnatron (but will not service the unit for you).
contact GE and they will take care of you... the magnatrons are warranted for like 10 years....

The problem is one of the door switches has failed, usually caused by food partical buildup, switch must be replaced for normal operation.

BAD DOOR SWITCHES AND UNDERSIZED WIRING TO THEM

I have a FNCB115GC Microwave problem. The microwave has a icon on the left hand side of the panel that looks like a opened book on a stand with lines on top. This is best that I can descibe it. The microwave turntable does not move or the microwave does to come on but the light comes on and the timer will count down. I have cleared the microwave and unplugged it with no results. Please help. Thanks in advance.

Check the door latch mechanism the black nylon door catch may be broken.

Quite often this is due to a bad door switch. Opening the door while cooking (without first hitting the STOP pad) is the primary cause of door switch failure. If you or a friend decide to work on it, we have *critical* safety, disassembly, and troubleshooting info (as well as a text file which helps in diagnosing and repairing door switch problems) at our site, which is linked at our listing here on FixYa: http://tinyurl.com/yzjozk

Quite often this is due to a bad door switch. Opening the door while cooking (without first hitting the STOP pad) is the primary cause of door switch failure. If you or a friend decide to work on it, we have *critical* safety, disassembly, and troubleshooting info (as well as a text file which helps in diagnosing and repairing door switch problems) at our site, which is linked at our listing here on FixYa: http://tinyurl.com/yzjozk