Problem
This troubleshooting article applies only to Post 2020 Machines
If the machine is not operating and the” information light” at the rear status panel of the machine and the firmware LED on the logic board flashes with the following eight-bit pattern as described here:
0000 1000 x-axis
0000 1001 y-axis
0000 1010 z-axis
Where 0 indicates a short pulse which is 1/4 second and 1 indicates a long pulse which is 1 second long.
This will be displayed in MotorScope as a “Stall Fault”. This means that the machine doesn’t move even though the motor is powered. This error can occur on all three axes but the debugging procedure is always the same.
Solution
The following items provide step by step instructions on how to break down the cause of the issue:
When the machine is off, push the axis by hand. If it is very difficult to move the axis then:
check the lead screw, axis alignment, coupler, or band drive, and contact Micro-Vu support.
Turn the machine on and press the E-Stop. Push the affected axis by hand. Strong braking should be felt when the E-Stop is pressed. Turn the machine on and release the E-stop and place the machine on Standby. Push the affected axis by hand. Braking should be weak compared to strong braking felt when the E-stop is pressed. Compare the braking between both scenarios. If the braking when the E-stop is pressed is weak (compare to the working axis), or intermittent, then one of the following has a hardware issue:
Motor Cable
Motor
Amplifier Board
When the machine is running and idle, push the affected axis. It should serve to resist motion.
If the axis is very easy to push, then one of the following has a hardware issue:
Motor Cable
Motor
Amplifier Board
The cable between the Logic Board and Amplifier Board
Logic Board
If clearing the Stall Fault causes another axis to jump:
The motor or encoder cables are mixed up between the axis.
Push the axis and watch whether the encoder values in MotorScope count correctly.
Press the E-Stop and unplug each motor cable in turn to make sure that the braking corresponds correctly.
If the Stall Fault stops occurring with certain motors disconnected:
There is a short somewhere in the motor, cable, or Amplifier Board:
With the machine off, check for electrical continuity between the motor leads and the chassis of the machine. It should be an open circuit.
If not, there is a short. Unplug the machine immediately and contact the Micro-Vu support!
Perform these troubleshooting steps for for a complete Axis evaluation:
