Happy New Year, everyone. Thank you for your hard work. I disassembled the internal diagram of 4Pro for your reference. The dmesg log works normally under the Android system.
The working process of WIFI/BT (AP6275PR3)/LED (tca6507) under the Android system. I hope it will be helpful for the repair work.
The AP6275PR3 chip debugging literature is for reference:
photo and dmesg log:
4pro-dmesg.log (368.0 KB)