Brother International HL-1660E Service Manual - Page 88

M-4 Malfunction of control panel switches. Possible cause Step Check Result Remedy Mis-operation 1 Are the switchs operated according to the operation manual? No Operate the switches correctly following the operation manual. Switch 2 When a switch is pressed,does the voltage of Yes Control panel PCB the following signals change from 5V to 0V? Signal No Main PCB Panel PCB SW8(SEL) P1-8 --- P1-14 SW7(MODE/EMULATION) P1-10 --- P1-12 Switch flat cable SW6(FONT/ECONOMY) P1-12 --- P1-10 SW5(FORM FEED/FEEDER) P1-14 --- P1-8 Main PCB SW4(SET/COPY) P1-16 --- P1-6 SW3(CONTINUE/SHIFT) P1-18 --- P1-4 SW2(DOWN/RESET) P1-20 --- P1-2 SW1(UP/TEST) P1-21 --- P1-1 Replace the Main PCB assy. Replace the control panel unit or the switch flat cable. M-5 Malfunction of buzzer Possible cause Step Check Result Remedy Operational error Main PCB Buzzer 1 Is the "Buzzer on mode "selected according No to the operation manual? (To alternate the buzzer on/off mode selection, press the MODE switch and select the "Advanced mode ".) Set the buzzer on mode. 2 Check the buzzer signal with a oscilloscope. Is the pulse of 4KHz output? Yes Replace the main PCB assy. No Replace the main PCB assy. M-6 "12 COVER OPEN" is displayed even if the upper cover is closed Possible cause Step Check Result Remedy Upper cover Main PCB 1 Does the upper cover hook press the actuator No Replace the upper cover assy. of the interlock switch on the main PCB correctly when upper cover is closed? Yes Replace the main PCB assy. VI - 12