By examining IC15 damage is found, its output voltage is 0V 14 foot intact. But without the same type of device, had to find another way. Judging from the circuit, B55614 foot function is to operate according to the output of a transformation of high and low level signal, it possible to replace it with other circuits? In theory, as long as the output of a high and low level control signal primary circuit, you can enable the machine to restore normal function. After measuring, and other integrated circuits in the circuit the pins without output voltage is found. IC11 pin voltage changes detected after IC15 pin voltage coincides with the normal state change instead, so plus the circuit shown in Figure 1 to replace a damaged B556. The principles are as follows: normal standby mode, voltage is 0V IC1114 feet, making inverter 14-pin output high of 4069, Q30 base voltage too high; recording, IC11 14 pin voltage becomes high, turn inverter 2 feet into low level; later, after recording 14 feet back to low level. Then disconnect the IC1514 foot connecting with the original circuit, the figure 1 circuit access, try troubleshooting.