problems with my microphone input

hello, I have problems with my microphone input, plug the mic input. and not hear the mic. if I put the input to half the input so if you listen. Does anyone know what is happening?

Do you have a Condenser or a Dynamic mic?

If you hear it putting it only half into the jack :

Do you perhaps have a stereo connector on you microphone ? Then you keyboard needs a mono beiing inserted. Or vice versa

thanks for the reply, does the microphone that you use in your Ketron, is condensed or dynamic?

thanks for the answer, what is the monkey beiing insert? the keyboard connector for stereo microphone if, but I hit a stereo jack and then the microphone input cable, and still giving me the same problem. only hear if you leave the input half.