Thanks for your suggestion, by the way I've tryed updating three different 2560 (of two different producer) without success... the bootloader is updated but the AstroEQ-ConfigUtility continue to fail reading eeeprom.
I've tried also to clear eeeprom with an Arduino skecth without results.
I've tried to update firmware, unplug the 2560 and go on but, in some situation, EQMOD permits the connection the the driver, AR and LST keep scrolling and none command will effect. I believe the problem is that the EEPROM is empty, but how could be modified if AstroEQ-ConfigUtility doesn't work?
Now I have ask some friend if someone got a 1280 and I'll try again... but I'm quite sad for this behaviour.