Apple Logic Pro /LogicExpress Discussion

Hi,

I'm new in this club and new to Logic Express. It seems that I have a problem which is been 
welknown for Logic, I have signal from my ext. keyboard but no sound from the internal 
instruments. I already looked to so many forums and websites, but I still can't solve my 
problem. 
The version I use is Logic Express 7. I already tried to QT synth but it also didn't worked :(  

you prolly see what I'm asking for, some kind of help for this poor dude :)