I am having the same problem. Mine worked fine for about a day. Then I disconnected it from Dobot Studio, turned off the power, unplugged it, and moved it to another location. Reconnected everything back, and then the LED stayed red/orange, no matter what I do, including pressing the reset button.
Then, I went into Dobot Studio, and connected it. It connected fine. But it would not respond to any command (the arm drooped down; i.e. no power to the stepper motors). Then inside Teaching and Learning screen, I could still use the arm unlock button to get coordinate entries. However, all the entries have the following coordinates (X, Y, Z, R) = (351.7873, -0.1625, 8.3079, -0.0265). This seems to indicate that the angle sensors are not working or the MCU is not reading it correctly.
Any suggestions on how to get this thing working again?