MPG(Some call it Handwheel or pendant as well.) does not work

CNC Control system of the CKA6150 CNC lathe machine:

GSK980TD/DA98A, double speed spindle motor, 4 station tool post

(Other CNC controller like GSK980TA,GSK980TDa,GSK980TDb, and AC servo driver DA98,DA98B, DA98D, same solution)

Problem Detail: Press the MPG key on the CNC controller panel, there is no “MPG” letters display on the screen, check it again under the Diagnose mode but the same problem, so the problem should be in the CNC controller. Check the MPG key with universal meter and found that the key is fine.

Then detected that the wiring between the key and display PCB board is open. Finally we found that there was a cold solder joint on a pin of the key panel, this connects the display PCB board and key panel, which caused the problem, the MPG resumed after re-soldering.

Conclusion: Sometimes the MPG does work due to the cold solder joint on a pin of the key panel.

How to find out the MPG is broken or not?

Turn on the 5V power of the MPG, universal meter connect to 0V, another end connect tp A,B pulse of the MPG, rotates the MPG gently, the reading of universal meter voltage should be range from 0~5V. otherwise it has problem.

Oscilloscope can detect the same and more clear.

External MPG

http://www.cncmakers.com/cnc/controllers/CNC_Accessories/MPG.html