OpenRB-150 fail to run MX motor

Hello, I cannot operate MX motor using OpenRB-150 with DYNAMIXEL2Arduino library sample code, while it does work on Arduino Mega.
I’m trying both MX-64AT and MX-64AR (with communication bridge and 12VDC power),
The Dynamixel Red Led lights on constantly, the code loop runs (I added a yellow LED blinking feedback). But no actual communication with the motor.
The DYNAMIXEL Wizard 2.0 that runs through the OpenRB also fail to detect the motor.
Measuring the TTL pin with a scope shows that no signal is transmitted.
Any suggestions?

It seems like a similar problem that described in " OpenRB-150 no longer recognises Dynamixel XM430-W530:" below.
Sorry for duplicating.
In my case the OpenRB was never communicating with the MX motor. Both board and motor are new.
The board QC number is 2320

have you change the jumper ?

Yes, thank you.
I also measured the 12V on the TTL connector, but as I mentioned, monitoring the TTL signal pin showed no transmitting while it should run the motor.

Update: monitoring the Microchip processor output shows a correct signal on the TTL output route.
Monitoring right after R16 resistor showing no signal. Additional inspection of the board indicate a short of the 5V circuit.

Given the result of your signal tracing, this is something that you’ll need to send in for inspection and repair, especially if the board behaved this way right out of the package. To complete this process, you’ll need to submit an RMA request form to the appropriate channel for your region:

When submitting your items for RMA service please be advised: in the event that the units are not covered under warranty you will be responsible for the cost of shipping + repairs (labor/components) before ROBOTIS may return the RMA units.

To proceed with RMA service fill out the the appropriate form from the list above to open a request with your region’s RMA team. In addition, you may find the troubleshooting self-checklist useful to assist in filling out the RMA request form.