[Forcedinduction]

I have a J325 with the Dynapath Delta 20 control and SD 1525 drives. A few weeks ago, I powered the machine up but did not do a reset to power the servo drives. After a few minutes, I smelled smoke from the main control cabinet and shut the machine down. The control display was still on and looked normal. Opening the cabinet revealed no visible smoke, fire, etc.

Finding time recently to check things out, the only suspicious looking component was a resistor on the control power supply. After pulling it off and examining it closer, the resistor hadn't been overly warm, so I went ahead and bench tested the supply for about two hours with a 5 amp load on the 5 volt output. Finding all outputs in spec, I reinstalled the PS and fired the machine up.

Everything appears normal, no smoke either. But when I press the reset button and power the servo drives, all three axes runaway until the machine trips off.

I started troubleshooting by unplugging all four axis cards. All the Dynapath supply voltages are correct and the +- 15 volts and bus voltage of about 104 are present on the drive chassis. However, the control voltage coming from the controller servo drive card to the servo drives is nearly 12 volts on all four card connectors. I suppose that explains the runaway.

If I unplug the cable from the controller servo board, I can reset and power the drives with no runaway. I have spare Dynapath controller boards except for the processor. Swapping all the rest one at a time has had no effect on the runaway problem.

Any suggestions on what I might be missing?
Thanks.

[two95s]

I know this is a long shot since this post is so old but did you get this figured out? I am having the same problem.

[underthetire]

Runaways are usually caused by a faulty tach generator in the motor if it's in a single axis.

Sent from my SM-T813 using Tapatalk

[two95s]

x, y, and z all start moving as soon as I push reset. I'm using a phase converter and my incoming voltage is a little high so im going to get that corrected and go from there.