# pm940 CNC no power to x,y and z axis



## Douglas Michaud (Apr 6, 2018)

I am having a tough time trying to troubleshoot why I can not get my machine to power the CNC controller through the start button on the machine. I was wondering if anyone has had any trouble trying to configure there machines


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## countryguy (Apr 6, 2018)

Hate 0 replies...    I've never seen the inside of one.   Have you called the PM guys?   Could you trace the controller wires that are noted as power input and determine if they are AC or DC inputs?   From there if power goes in and nothign is coming out... start w/ fuses and basics.  Loose wires, wires that came off or apart (snags and pinch cuts do happen).


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## Douglas Michaud (Apr 7, 2018)

countryguy said:


> Hate 0 replies...    I've never seen the inside of one.   Have you called the PM guys?   Could you trace the controller wires that are noted as power input and determine if they are AC or DC inputs?   From there if power goes in and nothign is coming out... start w/ fuses and basics.  Loose wires, wires that came off or apart (snags and pinch cuts do happen).


Ok so I believe it is the DC contactor that turns the x,y & z axis controllers on. If the coil on the contactor is burnt out, I believe the contactor will not work electrically. It does work if I manually push the button on the contactor itself. Does that make sense to anyone out there?


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## JimDawson (Apr 7, 2018)

That makes sense.  If the coil is burnt out then the contactor definitely would not work.  But that would be a highly unusual condition, almost never happens.

You have a pretty good start on troubleshooting.  You now know that the stuff after the contactor works.  So that is a good thing.  So now the question is:  Why is the contactor not pulling in?

Maybe an E-stop button pushed?  Loose wire?  If you have the schematic, find out what is supposed to energize the contactor coil and find the point that you are losing the signal.  You're almost there.


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## Douglas Michaud (Apr 9, 2018)

After giving it more thought, I realized when I rigged the machine I manually moved all axis’s to put the machine in a more balanced positioned. In doing so, the limit switches are not activated. When I fired up the machine and downloaded Mach3 and configured it, the software can’t tell where the machine is at. I think I need to bring the x,y & z back to home and see if that works


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## magicniner (Apr 9, 2018)

Mach3 doesn't need the switches to be in a given state at start up, you can home all the axes from any power up position with the Ref All Home button


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## Douglas Michaud (Apr 9, 2018)

Ok I am officially stumped. I can not figure out why the contactor will not latch. I have checked e-stops, limit switches, loose wires, I’m stumped


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## JimDawson (Apr 10, 2018)

Do you have a schematic for the machine?  Grab a multimeter and figure out where you are losing the contactor energize signal.  One connection point at a time.  The signal starts from somewhere, and ends at the contactor.  Many times the E-stop switch is the problem, that's where I would look first.  I would expect to see power on both sides of the E-stop switch, relative to the common, if it's working correctly.


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## Douglas Michaud (Apr 10, 2018)

Right after I posted that last comment, I was testing all the circuits. There was a loose wire coming out of the DC transformer. As soon as I tightened it the one contactor started to latch. I’m assuming the other contactor that isn’t working has the same problem. Just need to trace the wires


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## Douglas Michaud (Apr 15, 2018)

Ok, one last problem I hope. I can not get my computer to recognize or operate the controller. Upon fire up, I get a DLL error and it says that it is going to ignore the controller


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## phazertwo (Apr 27, 2018)

FYI, there are a few 940 CNC guys that lurk in the PM specific board (including myself).  You may get quicker responses there.

The loose wire makes sense, if I were you I would check every wire you can.  I had a few problems that were due to loose wires, I finally broke down and tightened every connection I could find.  Totally worth it.

As for the controller, I would assume its a nMotion?  I never had trouble getting the nMotion to connect to XP or Win2k, I have a bunch of other gripes about it, but connecting was never a problem.  What OS are you running on the computer?  I'm guessing it's windows 7 or newer?

PZ


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## Douglas Michaud (May 8, 2018)

phazertwo said:


> FYI, there are a few 940 CNC guys that lurk in the PM specific board (including myself).  You may get quicker responses there.
> 
> The loose wire makes sense, if I were you I would check every wire you can.  I had a few problems that were due to loose wires, I finally broke down and tightened every connection I could find.  Totally worth it.
> 
> ...


I checked every single wire after finding the one loose. I am running Windows 10. After talking to new fangled solutions(Mach 3/4) they told me that the controller will not work with windows 10 and recommended a newer controller and running Mach 4


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## Boswell (May 8, 2018)

No surprise that they are pushing Mach4 .   I know on my PM-45CNC I had some issues with the controller (not sure if it is the same or different from the 940CNC) I  replaced it with a smooth stepper and a break out board. It was a very easy swap and no longer have any issues. I am running Windows 10 and Mach3.  look at this thread https://www.hobby-machinist.com/threads/pm-45m-cnc-setup-and-configuration-with-mach3.21179/page-5 starting around page 5 and you can see GaryL helping me to to convert my PM-45CNC to a smoothstepper. He went first and I and other have benefited greatly from that.  I have to believe that the PM940-CNC would not be too much of a different experience.


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## phazertwo (May 9, 2018)

There are many good options for controllers out there theses days.  There are a few other guys on the PM board, along with myself, that have swapped to an Acorn board.  It's made a world of difference with how smooth the machine runs, and I highly suggest it.

PZ


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## Douglas Michaud (May 9, 2018)

phazertwo said:


> There are many good options for controllers out there theses days.  There are a few other guys on the PM board, along with myself, that have swapped to an Acorn board.  It's made a world of difference with how smooth the machine runs, and I highly suggest it.
> 
> PZ


Would you prefer it over the pmdx boards that Mach is pushing?


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## Douglas Michaud (May 9, 2018)

Boswell said:


> No surprise that they are pushing Mach4 .   I know on my PM-45CNC I had some issues with the controller (not sure if it is the same or different from the 940CNC) I  replaced it with a smooth stepper and a break out board. It was a very easy swap and no longer have any issues. I am running Windows 10 and Mach3.  look at this thread https://www.hobby-machinist.com/threads/pm-45m-cnc-setup-and-configuration-with-mach3.21179/page-5 starting around page 5 and you can see GaryL helping me to to convert my PM-45CNC to a smoothstepper. He went first and I and other have benefited greatly from that.  I have to believe that the PM940-CNC would not be too much of a different experience.


Thank you for the help and support. It is much appreciated.


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## phazertwo (May 9, 2018)

Douglas Michaud said:


> Would you prefer it over the pmdx boards that Mach is pushing?



I don't know anything about the pmdx boards, this is actually the first I have heard of them.  I went with Acorn for a few reasons, first and foremost was because the manufacture of the board was supplying the software as well.  They are tested extensively together, and when there is a problem there is no back and forth between software issues vs board issue.  Second reason was for real time processing.  The Acon actually has a Beagle Bone computer on board that handles motion control, which means windows or what ever programs may be on your computer cannot interrupt.  Last is that Centroid is not new to the industry, they have been retrofitting old CNCs for ever, and now days they even have there own line of equipment.  Simply put, retrofit CNC controllers is what they do, it's relatively common to find a machine that has been retrofit to run Centroid in industry.  Also, they are in the good ol' USA, which is a huge plus for me.

For all I know the pmdx has most of the above... but I'll go for an industrial supplier every time.  Also remember there are others out there, if cost is a concern, I'd look into a Masso controller.  No computer needed, just plug a monitor and keyboard right into the controller and go.  People seem to be having good success with it.

Acon setup will set you back ~$350-$500 depending which software you get and if you need to buy/build a new computer.

PZ


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