Jl381a Firmware Link

: Corrupted download or unstable USB connection. Fix : Re-download the jl381a firmware from an official source. Use a rear USB port on your PC (not front panel). Disable USB selective suspend in Windows power settings.

: Windows drivers not installed or boot pin not shorted correctly. Fix : Install libusb drivers using Zadig tool. Set the device to “STM32 Bootloader” and replace driver with WinUSB. jl381a firmware

By dumping SRAM over SWD (if debug port enabled), you can find: : Corrupted download or unstable USB connection

The firmware runs a with:

: New firmware resets calibration data. Fix : Look for a hidden calibration menu: usually power up while touching all four corners of the screen, or enter a special button sequence (e.g., Back+Enter for 10 seconds). Disable USB selective suspend in Windows power settings

Always consult the release notes before updating, as some older versions (like PD.01.xx) may require a multi-step upgrade path to reach the newest version. Update Procedures