I turned on the ignition to start the motor and the tach (digital analog combo comander series ) did not turn on. I then turned off and then on again the iginition and pressed the m button and the and the digital screen display flashed reset and every digital setting went to '0" including the engine hour meter. The tach began to work and so did the digital readings. Now I do not know how many engine hours I have on the 150 Etec. What caused this to happen?