RAK5010 board not showing comport

Hello. i am working on RAK5010. i have 2 boards, one of my board is working fine. like i plug in the usb and board powers up and i can see blue led, and com port appears.
but on the second board all the sequence is same except there is no COM port. i have tried flashing it to the latest firmware. powering up using battery.
NO COM PORT,
NO DATA ON SERIAL PORT.
can anyone guide me on making this board work.

Bilal

Welcome back to RAK forum @bilalfakhar

On the board with issues, is it working before or not? Also, were you able to try different USB cable/port? When you flash the firmware - how did you upload it and what specific file?

Thank you for your reply. Okay i have powered up this board for the first time. i have tried data cable, (the cable is working with android phone). i flashed the firmware using J-link. on this link

index - powered by h5ai v0.30.0 (https://larsjung.de/h5ai/)

RAK5010_Latest_Firmware / RAK5010_20210223065027.hex