New MPCNC Rambo Communication Error

I’m building my first MPCNC router and I can’t get it to move. The printer is connected but every time I try to make a manual move I get the error “Communication timeout-reset buffer block”. Here is what I know so far:

Rambo 1.4 board purchased from V1.
Firmware was installed by V1 and appears to be current revision.


My printer is connected to my laptop using Repetier Host, not Server.
I removed Repetier Server and it cleared my COMs error, allowing the printer to connect.

Windows 10
USB connection


When I use the manual control panel to jog X, Y, or Z, the G code gets generated, the commands get queued, and then I get the “Communication timeout-reset buffer block”.
This is a new build and has never moved so there’s something wrong with my setup, not a component that failed.

Any suggestions for a new builder?
Thank you in advance for any tips you can provide.

I don’t use Repetier, but I know that if you installed Repetier server then it will grab the serial port and not let Host use it.

I would probably try something else to check the serial port. Putty is a free client that supports serial communications (As well as ssh and telnet) and I’ve used it to check serial communications often. You should be able to set the serial port and baud rate easily enough to check that quickly. It is not a gcode sender, though, so it can only establish and verify a serial link. You can send simple commands though. I would probably suggest that you try some movements like:

G91
G0 X10
G0 Y10
G0 X-10
G0 Y-10
G90

which should move the machine around in a 10mm square.

If Putty doesn’t work, then there’s a more fundamental communication error.

I suspect it isn’t actually connected like it says it is. It should print a bunch of info when it connects and reset the controller. At that point, there isn’t much that should cause that comms timeout.

What OS is it? Windows 7 needs a driver. I think it is fine without in windows 10.

Are you sure you have the right port?

Thank you both for the quick responses. I just hooked my laptop back up to the printer to test both of your ideas and now X, Y, and Z all work. Maybe I had to disconnect and reconnect the cables for the COM port to get freed up after removing Repetier Server. Either way I can continue the setup and testing.

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