Acer Aspire V5-531 V5-571
Free Laptop Schematics
The 3D3V_AUX_S5 comes from 2N7002KDW Q1901 that was transform from 3V_5V_POK_# with a low state from KBC/SIO from pin 3V_5V_POK hight state and RSMRST#_KBC low state.
If RSMRST# does not drop to 0V on power button and KBC/SIO pin RSMRST# then change KBC Controller.
If the notebook got back light in the keyboard, take out the cable in that case you got no power or the power led blinks if you press the power button.
This problem appears when there was water damage in the keyboard and the keyboard got back light. It creates a short in those back light led`s and stops the notebook from powering up.