If the phone still shows signs of life (like a vibrating motor or backlight), you can try the HardReset unbricking guide which suggests: How to Open Recovery Mode on OPPO Reno 11F
This technical paper explores the causes and recovery strategies for an Oppo F11 (CPH1911) that has entered a "dead" or hard-bricked state following a failed firmware flash. Analysis of Post-Flash "Dead" State in Oppo F11 (CPH1911) 1. Introduction oppo f11 dead after flash
If you're going to attempt a DIY revival, ensure you have these ready: Look for the specific CPH1911 version. If the phone still shows signs of life
: Flashing a ROM meant for a different model or region. oppo f11 dead after flash