I have a TRB140.
On the Power Socket DIN4 i have 24VDC - the same like 1/2 - supply.
When the DIN4 is TRUE (24VDC) the TRB didn't boot - only one light is on.
If i disconnect the DIN4, the TRB normal boot.
When the TRB is up and i set the DIN4 to TRUE - everything is ok - also display in the WebUI.