Geeetech

Hi,
I had been using my GeeeTech I3 Pro (which has the GT2560 motherboard) without any problems between January and December 2017. But I was away then until recently and when I went to use it again, I found that the Repetier software could not communicate with the printer. It will connect but when it does, it reports the following error and the printer will not respond to any manual commands:

Serial com error: System.IO.Ports.SerialErrorReceivedEventArgs
No start signal detected - forcing start

I've checked all the obvious possible causes, the port settings (baud rate, etc) and also tried reinstalling the firmware but the problem remains. In desperation I have even tried it with another computer but again without success. Also, in the event that it's a hardware problem I have ordered a spare motherboard but it will be some time before that is delivered and I have a job waiting to be completed.
If anyone could offer advice on how to solve the problem or confirm that it is indeed a hardware problem I would greatly appreciate it.
Thanks in advance.

two possibilities.

first: wrong baudrate. try to use 115200 or 250000 baud. reinstall the FTDI or CHA driver wich uses by the printer.
second: you wrote you try it on a other computer with the same result. Same error?
third: you can try to connect the mainboard to the arduino ide to see what happens at the serial monitor.

und macOS you can open a terminal and see the devices with: < ls /dev/tty.* >
with < screen /dev/(your USB device) 115200 > you can try to connect.

But I'am thinking that the mainboard could be have a damage.

Maybe write what transmission parameters you have set.
Have you used the same USB cable on both computers?

Hi to fix your communication problem is to reboot your computer with the printer disconected and then turn on your printer and plug in the usb
On arduino 1.8.5 go tools wifi 101 firmware update and see if your usb is showing there. test your conection. If your usb is not showing there reinstal arduino. your gt2560 board is ok .Hope this helps John