182. Errors checking mode (Displaying the protection history)2.1. Operation specificationsError mode (Displaying the protection history):When the set is started up in this mode, the error information is displayed.Starting up:When power is turned on, presssing both buttons [PRESET+] and [STATUS] at the same time for 3 seconds or more.Protection history mode is set. In this mode, information shown in the following sections is displayed.2.2. About the display on the FL displayInformation about the last Protection operation is displayed.(1) Normal (when there has been no protection incident)FLD N O P R O T E C T(2) For ASO (when the last protection incident was ASO protection)FLD P R T : A S OCause: The line between speaker terminals is shorted, or speakers with impedance of less than the rated value.Supplementary information: As the excess current is detected after operation of the speaker relay, a short on thespeaker terminal and the connected speaker can be identified.(3) For DC (when the last protection incident was DC protection)FLD P R T : D CCause: DC output of the power amplifier is abnormal.If the power is turned on without correcting the abnormality, the protection function will work about 6 seconds laterand the power supply will be shut off.(4) For THERMAL (when the last protection incident was THERMAL(A) or THERMAL(B) protection)FLD P R T : T H E R M A L AFLD P R T : T H E R M A L BCause: The temperature of the heat sink is excessive.If the power is turned on without correcting the abnormality, the protection function will work about 4 minutes laterand the power supply will be shut off.(5) For Power(when the last protection incident was Power protection)FLD P R T : P o w e rCause: The Power Supply(±12V) is abnormal.b Additional causes of protection can be due to loose connections, associated components, Microprocessor, etc.When the "STATUS" button is pressed again after the above protection history as shown above is displayed, the normaldisplay reappears.