I'm having some issues with a machine BOSCH CC200.
The control panel unit was damaged while connecting the CC200 machine with the PC via RS232 cable.

At first we managed to fix the control panel unit by changing some TTL circuits and fixing the board wiring.
But the same thing happened again during the second attempt, and because we were missing some integrated circuits we had to buy a new panel control card.
We paid for it and it arrived. But after we installed it, again we had problems with the RS232 connection, which worked perfectly with the old control board while it was still functional.
We checked all the settings, but we keep getting the same message "i/0 timeout".
Is there anyone who can help me with this? Thanks in advance.