Casio CZ/ VZ/ FZ - Pro Series

>These problem begins to apear after some days that a ised the Cz 5000 for a
>long time of programing ( 3 or 4 hours playing with it without turn off )

Often a symptom that appears after a certain length of time is the result of 
something overheating.  Start by checking the power supply: check that the 
voltages are appropriate and without excessive ripple, and that nothing is 
blown or overheated.