The machine be watching before being struck by lightning, lightning from power. Teardown check, no obvious traces discharge. Tracking lightning invasion route inspection with resistance measurement method, and the power switch pipe line and output have been breakdown short circuit. After replacement, boot test, the power indicator lights, switching power supply has the vibration, but without grating sound. Significantly on the high side switch power supply output voltage, voltage 90 v to 140 v; 20 v voltage rise of 26 v. Change the voltage stabilizing circuit SE090 and photoelectric coupler is invalid. Disconnect the load on the 90 v end, parallel 60 w bulb do dummy load, voltage from 140 v to 110 v. Analysis is load circuit fault, more for the line scan circuit does not work. Check the line drive pipe be damaged, oscillation AN5192K {51} feet only around 4 v supply voltage. Check the power supply circuit power supply and step-down resistance is normal, measuring {51} feet of small resistance, doubt AN5192K after a lightning strike damage. After replacement AN5192K and line drive pipe, the machine back to normal.Vkwservice manual download site