Bord UART 6 stopped working and fastboot flash failes sometimes

I flashed the board a couple of times using fastboot. But now the uart doesn’ t give an output anymore when i use board recovery or anyhting else. It does go into fastboot mode and the pc sees android boot loader. But the flashing fails for some files and still no uart output. What to do ?

This is my second hikey 960 which has an sec 740 chip instead of my first one with has a SK hynix chip.

What happens when you switch the board in recovery mode [1] ? are you able to see a new ttyUSB eumerated when plugging USB (type-C), If yes, are you able to perform the recovery procedure ?

[1] https://www.96boards.org/documentation/consumer/hikey960/installation/board-recovery.md.html

I can do the board recovery there is only no output from the uart. So yes there is a USB connection

Does the UART adapter work with your other Hikey ?

yes. I also connected the uart to an oscilloscope and there is no data transfere. Only a fixed voltage.

Weird, so maybe we could consider your UART dead…
After recovery (recovery-flash.sh), you should have access to fastboot, then what is the ouput of Android flash-all script ?

Flashing works the board is send back for replacement. Thanks for your time