ACER V5-471G laptop does not boot share

An acer V5-471G notebook can not start up, connect the dc power supply, the standby current 0.006A, press the power button, the current up to 0.02A, Keep 2 seconds, then return to 0.006A, the power led does not light. Open the laptop, check the operating conditions for RT8223, VIN 19V, test 3.3V_AUX_S5, 5V_AUX_S5, both ok, 3.3V_PWR and 5V_PWR have not voltage. So check timing sequence.

Several signal must come out before 3V\5V comes, test +3.3V_RTC_LDO it is  3.3V, +RTC_VCC it is 3.3V, +PWR_SRC it is 19V, they are normal. Test S5_ENABLE, the voltage is 0V. .... read more