Tips: This only for old BST PCB Adapter customer, if you seen "V1.1" on BST PCB Adapter back side, thats means new pcb adapter you had!

BST-Android 4.4.2 UART Failed Solved

After upgrade 4.4.2 android OS, cannot communication with uart cables, but 4.3 uart communication working fine, try to solve problem as follow ways please:

A. Required materials and tools:
1). Resistor: R104(100K)
2). Soldering tool

B. How to solve:
1). Take BST Adapater( disconnect usb cables), solder R104(100K) resistor as follow point: