fisher hf x ray problem

i need your help i installed a x ray system with generator fisher RSX 30 HF in mexico, the equipment was installed in usa i bouth it and inport to mexico all is ok just every day or later of log time without use that turn on the system show: version of equipment, "read eeprom" , "calibrating" and in this time appear E12 error in calibration mA
if i not turn off the system later of 5 minuts aprox the equipment go to "initialiting" and the system work perfect all times that turn off and turn on but later of varius hours or next day the E12 apear again any help will be apreciate thanks and best regards every body