Hi Alan, I am working with a PUMA 560 and I am getting a "no zero index" error on joint 2.  The Shoulder joint went limp after it bumped the table (at speed 30) while we were teaching the PUMA how to play JENGA.  Any advice about troubleshooting?  I can't look at it until tomorrow, but just in case...you don't happen to have any PUMA parts that I might be able to buy?  

I am sick to my stomach. I broke my friend today.  We are supposed to perform in an improv comedy show at the Fusebox Festival coming up in April (Austin,TX).

OK, I'll start with an explanation and then some things to try.

Each motor has an optical rotary incremental encoder attached to the back of it. The encoder has some light source(s) probably LEDs. It also has a system that produces three output signals: Phase A, Phase B and Index. The phase A,B change a lot during one rotation of the motor. Like 800 or 1,000 times. The Index only changes once per revolution. So it sounds like that's your problem.

I don't know if the encoder is working at all. It could be that the A,B and I(ndex) signals have all failed.

So, what to look at?

I always unplug the main cable from both the arm and controller, look at it, blow on it, shake it and plug it back together. Good luck.

Then, Oh hey, does joint-2 make any noises when it tries to move? Does it try to move? Maybe you blew a fuse or a motor driver. MAN, not being there makes this hard. I guess there's even MORE I don't know.

How about describe what works, what you are doing when you get the "No Zero Index" (running potcal or something?) what you hear, if anything moves etc and we'll go from there.

Next I would open the controller, unplug each card, plug it back in a few times, power everything up and try again.

And, I sold all my Puma stuff when I moved, but the guy who has it might sell parts if you get in a jam.

Thank you so much for the prompt reply and thorough explanation!

I am on break from work now, but will see if I can get into the workspace tonight.  God willing, it is just a fuse.  

In the meantime, Let me give you the requested details and maybe you can tell me more:

Joint 2 doesn't try to move, and I don't think it is making any noise. All the other joints work just fine, but joint 2 went limp after it pushed down on the JENGA tower from above for about a second.  I hit the panic button on the teach pendant, but not soon enough. 

We were later able to turn the PUMA back on, hold the arm up so that the joint was in range, calibrate, and then move all of the other joints with the teach pendant.  But from Joint 2 there was no movement.  Then it was time to quit for the night.

Here is the actual screenshot of the error:

https://drive.google.com/open?id=0B7fAMYwVkD17U2RGUFNXVDljLWtfUm9FQm1ySVNZcm5TcFlF&authuser=0

Thanks for the troubleshooting manual, here is a photo of the section of the manual that relates to this error, page 46:

https://drive.google.com/file/d/0B7fAMYwVkD17WS1yWXI2Wi1ZNUpJOUJGRWlha1ROSEFES0lv/view?usp=sharing

Can you pm on hackaday?  I'd love to reach out to the new steward of your PUMA to start talking parts.

The only other source for parts I know of is RP Automation:

http://www.rpautomation.com/PUMA560RobotParts.aspx

Update:

The fuse for Joint 2 was indeed blown.  Dropped in a new one, but still can't get it to go past initialization, just keep getting "Joint out of Range" error.  But the brakes are on for all motors at this point, therefore I can't maneuver it back into range to get the Teach Pendant working. 

So I guess I've got to back the set screw off for #2 and manually rotate the shaft for Joint 2 until it's back into range.   I'm going to give it a go tomorrow night probably.  

Also, this document (which took forever to download for some reason) talks about diagnosing index issues:

http://theatronics.com/uploads/TroubleShooting.pdf