You might have heard of an "EDL deep flash cable" – a modified USB cable that shorts the data lines. Generally, no . For models launched after 2019 (including Redmi 9), the deep flash cable trick only works if the bootloader is in an unstable state. For a true hard brick, the physical test point is the only reliable method.
On the Redmi 9 (lancelot), the EDL test points are located near the , close to the flex cable connector for the sub-board.
For advanced users only. You need the correct ( prog_emmc_firehose_Sm6115_ddr.elf or similar for lancelot).
Look for a pair of dots just west of the main camera connector, about 5mm from the board edge.
To use the test point method, you will need the following tools: Xiaomi Redmi 9 Power EDL Point - GsmClinic.com