FOLLOW THIS STEPS: * run hydratool mtk module * select brand and model cph1823 (oppo f9 ) * in coinnection choose ATE mode * service tab then imei repair * paste or type imei number then check * power on the phone and enable developer option ,goto advance settings enable oem and debug mode * goto dial menu then type *#800# wait for promt pop up on screen * tap ATCI and TAP Enable * back to hydra tool software select mtk port the execute imei repair * then restart the phone manually then dial *#06# check the imei and youre done