Geeetech

Thank you for your suggestion.
I borrowed a Windows PC and tried it out.
The results were the same.
I guess that you are correct -the FTDI circuit has a problem, and the board will need to be replaced.

Thanks again.

Hello.
Yes, I have installed the drivers (for Macintosh).
1. From the first power-up, the controller board has been able to transmit to the Macintosh (the power-up message, and the files on the memory card are displayed on Repieter).
2. The printer's controller board does not receive information ...

In case this thread helps anyone, I thought that I would continue with my story.

Over the telephone, I told Geeetech my problem with the display board, and they immediately sent a replacement display board and cable.
I installed the new display board, and it worked.
Using the display menu, I ...

1. Yes, I have the correct Baudrate (remember, I do have proof of communication between computer and control board because I get the message:"FIRMWARE_NAME:V1.0.02 PROTOCOL_VERSION:V1.0 MACHINE_TYPE:Rostock301 EXTRUDER_COUNT:3 UUID:" on my computer).

2. I have tried re-connecting the ribbon cable a ...

Hello.
I completed my 301, and it seems fine mechanically.
The Electronics have, unfortunately, a problem.

1.0 The Control Board:
Upon connection with Repetier, the Control Board sends its Boot-up message perfectly ("FIRMWARE_NAME:V1.0.02 PROTOCOL_VERSION:V1.0 MACHINE_TYPE:Rostock301 EXTRUDER_COUNT ...