Maylord.war wrote:The c8 and c14 in my pcb are ceramic (not polyester) , is a possible cause?
No, as long they are good and of the right nominal.
And the c12 in my pcb is ceramic and have the sigle 102 ( =1nf) , i see the quick manual and the c12 capacitor is 100nf polyester, is an error?
You have to make sure yourself that the nominals of all parts are correct.
I have soldered the ceramic capacitor because I had not received the polyester in the kit.
I'm not expert but the difference from ceramic and polyester make this difference (noise in my case) ?
No.
I must say, tracing a cause of intermittent electrical problems is very difficult. It could be wrong/faulty parts, bad soldering, bad shielding and etc.