We use this robot for milling wood pieces and have had no issues for a while. Recently, in the middle of program execution, the robot simply stopped.
TPU stated it had lost communication with the control. The control was turned off and after some time was turned back on. After the restart, I got a message that the control had lost the calibration values. I was able to jog the arm away from the work and moved all axes back to the calibration position (aligned all the vernier scales for an approximate location). I then replaced all the calibration values in the parameters (factory settings that were correct before the issue) and tried to reset the rev counters (resolvers). After a restart, no change.
I tried to run the calibration utility, but got the error message #50140 "heavy payload caused static torque limit to be exceeded on joint rib_2". The robot is rated for 150 kg. and I'm running a 50 lb. spindle, so I don't think I'm stressing the machine. And it wasn't a hard crash; the communication between control and manipulator just quit. The remedy accompanying the error stated that I should "reduce the payload or reduce the working range to decrease the static torque due to gravity". And now I can't move the arm at all.
Having checked the values in the parameters and in the jogging window, its clear that axes 2, 4 & 5 are out of working range; in jog mode in calibration position, the values for axis 2 is 331.6º, axis 4 is 313.7º and axis 5 is 121.3º.
The system came to us used a little more than a year ago from a reputable dealer with new batteries (amongst other things), and I've scoured the manuals trying to find a solution, but to no avail. Work is backing up and the boss is not pleased, so any help would be greatly appreciated.