No power to servos - DC310B

[calebkullman]

Thanks. Are there any other tests or troubleshooting we should try before we send the board in? I am planning to call in later today.

[centroid467]

Best way to troubleshoot the fiber optic TX/RX is to use an oscilloscope and check to see if there is a clean signal on the test points near the fiber connectors. On your MPU11 that would be TP1 and TP2, on the DC3IOB that would be TP11 and TP13. A suitable ground point on the MPU11 will be pin 4 of the jog panel connector (H2). It is a two row header and pin 4 is on the top row, easy to reach. TP2 on the DC3IOB will be a good ground point for checking on that side.

[calebkullman]

Thanks. I have to say you all really do a good job with this tech support - it is much appreciated. We have an oscilloscope - what exactly are we looking for on the scope?
More questions - what would be the pros/cons to upgrading this system to an Allin1DC at this point and trying to sell the DC310B and MPU11? Would we gain any performance from the controls by upgrading? It seems a little foolish to be putting a lot of effort into a system that is already 12 years old before it has ever been used. Are the fiber optics likely to give us trouble in the future?
Thanks again.

[wpaddock]

Thanks all, here are some screen grabs from the scope. In order from first to last;
DC310 TP11

DC310 TP12

MPU11 - TP1

MPU11 - TP2

I'm by no means an expert on using a scope, so not sure I captured what I needed to.
Thanks - Will

[tblough]

Well, if you had the same scope trace on both ends of the fiber, then the transmitter and receive pair on the fiber are working correctly and the fiber is not damaged. If you don't have the same signal, then either the transmitter, receiver, or cable is bad. The previous test of switching cables should have ruled out broken fibers.

[centroid467]

Thanks all, here are some screen grabs from the scope. In order from first to last;

DC310 TP12
DC310B_TP12.png
MPU11 - TP1
MPU11_TP1.png


I'm by no means an expert on using a scope, so not sure I captured what I needed to.
Thanks - Will

Ok, fiber 5 looks good - that is what I would expect to see. It looks like you might have gotten the wrong test point on the DC3IOB for fiber 4, however. Since there is no signal on the MPU11 end anyway even after swapping the fiber cables, I'd say there is something wrong with one of the boards.