Thanks very much for your reply Zavateandu

Unfortunately backup isn't an option as the rs232 is dead , I've checked all cables and settings and they all ok, that's why i want to look at the PCB i am sure the IC (chip) for serial communication on the port JD5A is faulty.

Do you, or anyone know how to use port JD5B instead?...According to the manual that port is the rs232 channel 2, but when i set the parameters to use that port, the LSK flashing light doesn't come up when i try to receive data, and nothing happens if i try to punch data out either, it seems like the port is disabled.

Maybe there is a keep relay or special parameter that enables the port I am missing, any clue about that?

I am attaching photo of all numbers i can get without removing the board