To see if your adapter is working, disconnect it from the STB and short the TX and RX pins on the adapter itself. Use a terminal program like PuTTY or Tera Term. If what you type is echoed back, your adapter and drivers are functioning correctly. Hardware Reset Timing
If your STB is completely dead ("hard bricked") and cannot enter bootrom mode via buttons, you must manually trigger it on the motherboard. Bootrom Error Wait For Get Please Check Stb Uart Receive
Windows 10 and 11 sometimes block unsigned drivers, causing the handshake to fail silently. To see if your adapter is working, disconnect
Locate the or the eMMC/NAND chip . (You may need to look up a schematic image for your specific board model online). Bootrom Error Wait For Get Please Check Stb Uart Receive