Here I have Shared ISP Pin Out for Oppo A3s purpose for Direct ISP Flashing, Factory Reset, Dump your Emmc Also can use for Backup the Primary partition of eMMC before Change.
Note : use batery or Usb cable supply for VCCQ and VCC more safety than soldering.
for eMMC dump file :
For firmware :
Be carefull soldering cause short solder occur damage your phone.