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New Home Forum Mostly Printed CNC – MPCNC Troubleshooting – MPCNC Display fades on and off continuously

This topic contains 47 replies, has 8 voices, and was last updated by  John 1 month ago.

Viewing 30 posts - 1 through 30 (of 48 total)
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  • #40942

    John
    Participant

    Hi again,?

    I flashed Marlin onto the board without issues.  If I plug the board only to the laptop USB, the display comes on normally and allows you to browse through the menu etc.

    If I plug the board to the MPCNC (12V P/S), when I turn it on, the display turns on, but it alternates between dim and bright, each time only showing the “Marlin” logo, and keeps doing that over and over.

    I have 2 sets of power going to ramps board as suggested.  Do I need to power the arduino 2560 underneath it seperately?

     

    Any idea what might be happening?

     

    Thanks

    John

    #40947

    Ryan
    Keymaster

    Check your power supply to see if the light is blinking on and off. Either a bad connection or bad power supply. A Picture of your wiring all powered up will let us have a look and confirm everything is correct.

    #40950

    John
    Participant

    20170813_091611
    Looking at it now, it seems there is not enough power.  Multimeter reads 12.5V going into the ramps board.  Motors are off. I can’t hear anything coming from the motors.  The LED on ramps board keeps flashing green continuously.

    #40953

    John
    Participant

    The power supply is a 12V 5A/60W

     

    Is this not enough maybe?

    #40954

    Ryan
    Keymaster

    That is more than enough. How about that picture?

     

     

    #40959

    John
    Participant

    I posted it above my other post.  If you can’t see it I’ll post it again, but I can see it here

    #40961

    Ryan
    Keymaster

    12.5v is good but it still sounds like yo have a bad power supply, I see the pic now, the wires seem right but, those are bad power supply symptoms.

    #40963

    John
    Participant

    OK I’ll see if I can find another P/S to try.

    At least now I know the wiring is correct.  Wasn’t sure if the arduino also needed to be powered seperately.

    Will keep you posted

    Thank you

    #40965

    John
    Participant

    UPDATE:

    I just blew the board or both the ramps and arduino, not sure.

    I have a bench power supply good upto 5A.  I just found out there is something wrong with it because it put out possibly upto 45V into the board.  I unplugged it and measured with meter and noticed the voltage went upto 45V.  The bench supply’s voltage meter wasn’t working.  Anyway, plugging it back into USB, there is no flashing green light anymore.

    I wonder if both boards are blown or how to find out

    #40966

    Ryan
    Keymaster

    45V?!, look for the burnt component.

    #40974

    John
    Participant

    Nothing looks burnt.  lights come on on the mega 2560 but doesn’t show up on the PC when plugged into the USB.

    I think it’s all dead.  Probably the drivers too I guess

    #40982

    John
    Participant

    Is it possible that I just burnt the poly fuses on the ramps?

    #41263

    Vincent Pollaro
    Participant

    It is possible. Looking at the thread, I think your initial issue may have been a failing 5v regulator. That would explain why they screen is correct when powered via USB, but flakey when powered via the 12v line. I have a RAMPS stack that has the same behavior and has been that way for 2 years. Normally not an issue, as when it is in operation I have both the USB (to a Raspberry Pi) and 12v from the PSU at the same time.

    #41446

    John
    Participant

    I noticed in some youtube videos the stepper plug has the wires  in the order of blue, red, green, black.  I have mine red, blue, black, green.  Do I need to change it to the first mentioned order or is it fine the way it is?  So basically the coil wires are switched on both coils of each stepper.

     

    #41455

    Ryan
    Keymaster

    Nope that just  reverses the direction they move.

    #41497

    John
    Participant

    Thanks Ryan,

    So I would just need to invert the direction in Marlin?

    #41499

    Ryan
    Keymaster
    #41716

    John
    Participant

    OK I’ll try that when my replacement hardware comes.

    Thanks

    #41717

    Jakob A
    Participant

    I might be wrong about this its a little bit hard to tell.. but it seems to me that on the picture the drv8825’s are reversed.

    1 user thanked author for this post.
    #41744

    Ryan
    Keymaster
    I might be wrong about this its a little bit hard to tell.. but it seems to me that on the picture the drv8825’s are reversed.

    OMG, you’re right. Thanks Jakob.

    John your drivers are in the wrong way, look at my picture vs yours. the little silver pots are supposed to be facing the power plug. Chances are really good those drivers are toast now but flip them and give it a try.

    #42316

    John
    Participant

    Thanks guys,

    I ended up replacing the whole electronics due to my smart actions last time.  Funny thing is the power supply (originally thought was the issue) now works after first trying the bigger replacement.  I don’t know why I couldn’t get the axis to move last time, but now we have action.  I had to swap green and black (or other pair probably same result) on one stepper per axis because when I tried moving the axis this morning, they moved in opposite direction, so just flipping black and green on one motor, fixed the problem.  This was the case for both x and y.  Don’t know where I went wrong in the wiring but it’s good now.

     

    I’m hoping to (if not cut anything today) at least get something to draw on paper to see some action, and much needed satisfaction.  Is there a youtube tutorial on what software to use (Estlcam?), what’s the easiest and how to use it.  Basically a tutorial on first use of the machine.  I know 3d printing pretty well, but I know absolutely (zilch) nothing about cnc cutting etc.

    You guys rock.  Your help is very much appreciated

     

    John

    #42317

    Ryan
    Keymaster

    Sweet, lets see how this works, https://www.vicious1.com/estlcam-basics/

    1 user thanked author for this post.
    #42320

    John
    Participant

    Ryan thanks for your fast reply.

    I still have some tidying up to do and hook up the spindle and speed controller, but either later today or tomorrow I should be ready for loading up some gcode and crossing fingers.

    Thanks again, will let you know how I go

    #42334

    John
    Participant

    I have just loaded the “crown” in the example and run it.  After a couple attempts I got it to sketch on paper.  A few little issues:

    1.  How can I predict or know where it will start to sketch/cut
    2.  Can you set a “Home” without endstops?
    3.  My sketch was drawn up-side-down

    Definately getting there.  BTW, I tried adding an endstop, but as soon as I plug it in to the board and try to move say 100mm, it only moves in short bursts and stops, almost seems like it’s  moving 5mm then stops, then you command it to move another 100 and does the same.  Unplug the endstop and all is good.  Weird

    #42340

    John
    Participant

    This is my best attempt so far.  The small circle isn’t really a perfect circle.  What do you guys think?

    #42372

    Ryan
    Keymaster

    1-It starts right where the tool is, that is “home”

    2-Hit reset on the board, boom, home.

    3-Flip your Y axis wire over, on the same page as that crown it gives a link to correct it.

    If you really want to monkey with and endstop either change the firmware or wire them normally open. Have a look at the FAQ’s and really think about how you would use an endstop when your work piece is never in the same place???

     

    #42402

    John
    Participant

    Great thanks mate.

    I’ve been doing some more drawing tests this morning and noticed at one stage the steppers were skipping steps.  So I checked the voltage on the drivers and they were around the 0.7V mark.  I know that’s pretty low, and without doing any measurements and calculations I upped them all to around the 0.91V mark.  No more skipping and the steppers stayed cold for the 10 minutes it was doing the job.  Since we all pretty much use the same steppers (Nema 17), is someone able to tell me what is a good voltage to set the pots to?  I guess I may still experience skipping when I move to cutting rather than just using a pen which has almost no force on it.

    #42427

    Barry
    Participant

    .7 is the standard voltage to set them to.

    #42439

    Ryan
    Keymaster

    You have drv8825 drivers? At .9V the drivers would be insanely hot as well as the steppers. It sounds like you have different drivers or you are wired in parallel.

    #42440

    Ryan
    Keymaster

    Skipping steps could also mean you are trying to move it to fast. If you are unsure upload your gcode.

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