Use tape or a rubber band to keep the button pressed. On many Xiaomi devices (MTK), you must hold Volume Down + Power, then release Power after 2 seconds, but keep Volume Down pressed.
That device disappears after 5 seconds. You need to right-click it while it is visible . how to install mtk driver mediatek preloader usb vcom
Crucially, the Preloader also listens for a USB connection in the first 5–10 seconds after powering on. When you connect a powered-off MediaTek device to a PC while holding a specific button (often Volume Up, Volume Down, or both), the device enters (BootROM mode). In this mode, the Preloader appears on your PC as a USB VCOM (Virtual COM Port) , awaiting commands from tools like SP Flash Tool. Use tape or a rubber band to keep the button pressed
Remember three golden rules: