The first thing I did is programming channels and flashing with new firmare. Everything passed ok, but GP340 still beeps.
I tryed with disabling alerts and found that this is button/keypad error alert. I checked all 5 buttons, and diodes near buttons, and all are ok. Then I changed cpu with new one, and still have the same problem

Does anybady know if it is hardware or software problem and how to solve that problem?