cnc mill repairs

[mikkhh]

Some 30-40 year old cnc mill had tooling setup error and mill crashed into jaws hard. After that there is spindle error. I was like okay, this has to be something with the spindle motor module.








Pulled the module out, fuses checked good. Then checked igbt module with multimeter diode mode and found out short between W and N legs . There should be not full on short circuit there. Then pulled the igbt module cover and looked inside for signs of burn or perhaps the schematic is just plain wrong.


https://www.ic-components.com/blog/6MBP1...asheet.jsp

This case there is actually burn visible under the gel.


Next step of action is trying to find another working igbt module, replace optocouplers (find if and where are igbt drivers, if possible replace them too) on board and check other parts of the igbt driving circuit. Maybe the igbt failed because of bad controls ? .

My theory is not good, I am not good at reading schematics (things I fix most of the times there are no schematics obtainable) but I have fixed all kinds of electronics before. I first first tv power supply board when I was 16. I have been involved with these things for over 10 years.

All that diagnostic took actually less than hour - started at 16.30 drove away 17.30.