hello,
i think your resolver unit is out !
the resolver's signals are multiplexed and converted before there are transmitted to the main computer .
it's a common failure ...
i repaired a lot of resolver unit board !
The resolver unit?? would that be the SMB?
I managed to get it up and running again, but only temporarily. I updated the rev counter for axis 6, and went into the program and drastically slowed down the velocity of the movements in the area where it was faulting out. We started back up, it ran great for about 15 cycles, then it faulted out again...in the same spot, with the fame faults. 
Intermittent errors frequently are caused by cabling/ connector issues.
Not sure what type of robot you have but worth checking all connections from resolver to SMB.
memiller : exactly the smb !
first, check all connection like said prnuk but i really think that's smb board !
If I remember correctly, I believe the resolver is inside the motor itself. The SMB reads signals from the resolver in the moter. You may need to buy a new motor.
Indeed, the resolver is in the motor but the conversion is done at the smb board.
depending on arm type the usual suspect is cabling. How many hours on the arm? What arm? SMBs are typically not intermittent.
Hello.
I repair smb modules.
I know how to repair the 38031 resolver error.
The price is cheaper, 230 euros.
The price is a half of other because i are owner and work for me.
I repair and probe the SMB board with a real robot with one year warranty.
Edit: email address removed by moderator. Please send this kind of information as a private message.
DID YOU EVER FIND A SOLUTION TO THIS PROBLEM
I AM HAVING EXACTLY THE SAME ISSUE
we have had that issue with our welding robot positioner ( IRBP R) replaced the wires and all good now.
Thank You cibex for Help
Robot works fine 
Hello.
I repair abb smb modules.
I know how to repair the 38031 resolver error.
The price is cheaper, 280 euros.
The price is a half of other because i are owner and work for me.
I repair and probe the SMB board with a real robot with one year warranty.
My email: removed , please use PM
I made happy some people, and i continue repair SMB boards and doing reverse engineering and learning.
Some people need a fast response with the problems, and fast response is my email.
Please dont erase this email, It is for everyone's benefit.
Email. chemajupiter@gmail.com
