Oppo F3 CPH1609
With Mtk chip but We can't boot with CM2 dongle or Vocanal Box
Just only MRT dongle support it
On MRT dongle choose MTK_Tools
Choose Format (unlock)
in Global Option tick Oppo Only
Other Option choose F3 only and click Start
for boot with MRT dongle just turn off the phone and hold volumn + and -
the process will start.
If not, do it again.
Ok, Hope this help.