Cannot open USB port on replacement board

K8200 3D Printer K8200 - Computer related problems
1

Hi All,

I just wanted to check with the wise and the good on this forum whether I am missing something before I return my replacement control board to my supplier.

I had a fault with my original board that was related to incorrect heated bed temperature readings, so I got a replacement sent out to me.

I fitted the new board and, before switching on the 15v power supply, I connected the USB cable to my Macbook and opened up Repetier. When I click “connect” I get the following 2 lines in the log -

16:01:03: Attempting to connect to printer
16:01:03: Couldn’t open port for device usbserial-A602YW6R

After several restarts of Repetier, unplugs of the cable etc, I tried the original board again and it connects correctly

16:09:02: Attempting to connect to printer
16:09:03: Connection opened

On both boards the green and red LED by the USB socket are lit when the USB cable is plugged in.

I have also tried powering up the new board. In this case the LED’s do not stay lit, but that is the same for both boards.

With the original board, when I connect from Repetier I see the USB LEDs flash with communication. With the new board I see the 2 LEDs flash twice ONLY when the USB cable is connected but nothing after that.

I have tried a reset on the new board which gives 2 flashes of a green LED by the XSTOP socket and one flash of the red USB LED.

I think I have tried all logical steps to prove that the new board has a faulty USB circuit but wanted to double check before I send it back.

Many thanks for any advice.

Peter

2

Problem solved…and thanks go to the Technical Services Manager at Maplin!

For anyone who is interested, the USB port that is listed in Repetier (on a Mac at least) changes depending on what is connected. I still don’t follow the logic, but the new board now connects as “usbserial-A702TPJB” (the old one was usbserial-A602YW6R)

Thought I knew a bit about these things, but you learn something new everyday!

3

Hi Peter,

the FT232R can submit a device ID code when opening the connection, and the driver will interpret this to determine whether it’s a known device (which will get the same port number than before) or a new one. So this behavior is quite ok, the driver simply does not know that actually both FT232R belong to the same type of device and that it would be ok to assign the same port number.

Cheers,
kuraasu