Is my controller board broken? (Geeetech Prusa i3 Aluminum)

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05-02-2016, 03:11 AM
SLCPUNK

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Is my controller board broken? (Geeetech Prusa i3 Aluminum)
Hey guys,

I just recently completed constructing my first 3D printer, a Geeetech Prusa i3 Aluminum, and I'm experiencing some problems I'm hoping aren't a bad control board. I'm hoping you all can help me identify what the problem is or might be and what to do to correct it. The control board that was shipped with the kit I bought is a Sanguinololu v 1.3a.

What works
- both the heated bed and the the heated part of the extruder
- the z-axis (although it sticks when I try to go up)
- the y-axis
- Both thermometers
- the lcd
What doesn't work
- the x-axis (when plugged into the x-axis controller)
- the extruder feeder (when plugged into the e-axis controller)
What I've done to try to fix and diagnose the problems
The first thing I did was plug the x-axis stepper into the y-axis controller and the x-axis stepper worked fine. Same thing with the extruder stepper, and it worked fine as well once plugged into the y-axis.

I hooked my multi-meter up to the y-axis and on the 20v setting it read 1 or less when I manually positioned the y-axis stepper. The e-axis read 0 at all times and the x-axis went as high as 12.

I made sure all the solder points looked good, and as near as I can tell there aren't any bridges or anything. There are some smaller control boards (not sure what to call them) on top of the larger one that I took out and inspected, and they looked fine as well.

What should I do at this point? I'm hoping it's not a fried board or anything, but I'm really not sure what else it could be since the steppers work great when plugged into different control sockets. Any help would really be appreciated. Here's a couple shots of the control board for what they're worth.

Here is a shot of the X Y & Z axis.
Attachment 9353

And here is a shot of the e axis.
Attachment 9354
05-02-2016, 06:50 AM
printbus

Was the hot end at printing temperature when you tried to drive the extruder stepper motor? Most if not all variations of printer firmware will prevent you from driving the extruder motor when the hot end is cold. If there is filament loaded in the hot end, preventing cold extrusions will keep your extruder drive from chewing into the filament or from doing mechanical damage to your extruder.

The small boards are the stepper motor drivers. There should be one for each stepper motor. On your x-axis issue, figure out which one of those boards is for the x axis motor and swap it with the board from another axis. This will help determine whether the stepper motor driver for the x-axis is bad.
05-02-2016, 10:18 AM
SLCPUNK

Quote:

Originally Posted by printbus

Most if not all variations of printer firmware will prevent you from driving the extruder motor when the hot end is cold.

Good to know. I can't recall if I had the element heated when I switched off the e-axis to the y-axis, so I'll have to heat it up and give it another shot.

Quote:

Originally Posted by printbus

The small boards are the stepper motor drivers. There should be one for each stepper motor. On your x-axis issue, figure out which one of those boards is for the x axis motor and swap it with the board from another axis. This will help determine whether the stepper motor driver for the x-axis is bad.

Do you know if I run the risk of damaging the y-axis stepper motor driver by swapping the non-functioning x-axis for this test? It makes sense to do it, but I'm concerned I'll break it.

If I do need new stepper drivers, will these work? http://www.amazon.com/Mcdectech-A498...0Y/ref=sr_1_12

edit: and thank you for the quick reply and help!
05-02-2016, 10:37 AM
printbus

Quote:

Originally Posted by SLCPUNK

Do you know if I run the risk of damaging the y-axis stepper motor driver by swapping the non-functioning x-axis for this test? It makes sense to do it, but I'm concerned I'll break it.

I doubt there'd be much risk, but it's your call.

Quote:

If I do need new stepper drivers, will these work? http://www.amazon.com/Mcdectech-A498...0Y/ref=sr_1_12

Please understand that I don't have a Geeetech printer or familiar with that control board. That said, the stepper motor drivers are pretty universal, but there are some variations. First, there are a couple of different driver chips that boards use; you'd want the new board to have the same chip as what you have now. I can't make out the part number on the square black part in your photos - are they marked with A4988, consistent with the part used on the Amazon board? I've seen two different pinout schemes to these boards; I can make out the DIR, EN, and GND labels on 3 of the 4 corners of one driver board in your photo, and this matches the photo in the Amazon listing. The pinouts probably match, but you could verify a few more of the pins that I can't read in your photo.

BTW - have you tried adjusting the trimpot on the driver board for the extruder motor? Maybe it's set to too low of a motor current. That'd be another thing you could try before committing to by a replacement board.

I'm happy to try and help. I don't like to envision people getting frustrated over unanswered questions.
05-02-2016, 10:48 AM
SLCPUNK

First, thanks a ton for all the help.

Quote:

Originally Posted by printbus

I doubt there'd be much risk, but it's your call.

The risk is like $2 in parts from Amazon, so I feel pretty good about trying it out at least :).

Quote:

Originally Posted by printbus

Please understand that I don't have a Geeetech printer or familiar with that control board. That said, the stepper motor drivers are pretty universal, but there are some variations. First, there are a couple of different driver chips that boards use; you'd want the new board to have the same chip as what you have now. I can't make out the part number on the square black part in your photos - are they marked with A4988, consistent with the part used on the Amazon board? I've seen two different pinout schemes to these boards; I can make out the DIR, EN, and GND labels on 3 of the 4 corners of one driver board in your photo, and this matches the photo in the Amazon listing. The pinouts probably match, but you could verify a few more of the pins that I can't read in your photo.

The photo of the product and the photos I have of my own motors look nearly identical, but I'll check tonight when I'm back from work. If I provide a more detailed image would you mind helping me verify?

Quote:

Originally Posted by printbus

BTW - have you tried adjusting the trimpot on the driver board for the extruder motor? Maybe it's set to too low of a motor current. That'd be another thing you could try before committing to by a replacement board.

I don't even know what the trimpot is to be honest. Is that the little screwable metal circle on the stepper motor driver?

Quote:

Originally Posted by printbus

I'm happy to try and help. I don't like to envision people getting frustrated over unanswered questions.

I really appreciate the help. Thankfully I got my printer in 2 days (from Hong Kong, go DHL) which was about 3 weeks earlier than I expected so I'm feeling good and way ahead of my internal schedule. I've got a Make 3D print certification class on Wednesday as well, so I may bring my printer to see if I can get some hands on help as well.
05-02-2016, 10:58 AM
printbus

Quote:

Originally Posted by SLCPUNK

The photo of the product and the photos I have of my own motors look nearly identical, but I'll check tonight when I'm back from work. If I provide a more detailed image would you mind helping me verify?

I'll be around. Note that we're talking the little driver boards, not the motors themselves.

Quote:

I don't even know what the trimpot is to be honest. Is that the little screwable metal circle on the stepper motor driver?

Yes, that's it. If your printer documentation doesn't address the trimpot, you can search the net for something like "stepper motor driver adjustment" for info on how to go about the adjustment. You'll likely need to adjust the trimpot on the replacement board if you go that route.
05-02-2016, 11:31 AM
SLCPUNK

Quote:

Originally Posted by printbus

I'll be around. Note that we're talking the little driver boards, not the motors themselves.

Yeah I mistyped there. The driver boards look identical.

Quote:

Originally Posted by printbus

Yes, that's it. If your printer documentation doesn't address the trimpot, you can search the net for something like "stepper motor driver adjustment" for info on how to go about the adjustment. You'll likely need to adjust the trimpot on the replacement board if you go that route.

Cool. Thanks again! Now I just desperately want to get home and tinker haha.
05-03-2016, 10:28 AM
SLCPUNK

Printbus, you're amazing. Thanks for all the help. I made some good progress last night and got both my z-axis to stop sticking going up by adjusting the trim pot and got my extruder stepper to work. You were right about my firmware preventing me from "cold extruding" so once I turned echo on in Repetier I could see that, heat it up, and now it's working great.

I'm still unable to get my x-axis working unfortunately. When I send it a move command it jerks a tiny bit but won't continue moving. The rods are straight and well lubed. If I push the x-axis manually I feel only a tiny bit of resistance from the motor. I think I may have something other than a bad stepper controller. I swapped the x-axis controller with the z-axis controller, which didn't appear to deliver enough power to the z-axis, and that controller worked perfectly in the z-axis slot. I'm still considering buying those stepper controllers from Amazon I linked to previously just to be sure (5 of them are only $12). I verified that they are the same controller. Are there other possible causes I could investigate for the x-axis not working that I can test out while waiting for those items to show up?

Thanks again for the help!
05-03-2016, 11:09 AM
printbus

Quote:

Printbus, you're amazing. Thanks for all the help.

I've simply seen a lot on my printer and on the printers I've helped others with, and usually have some spare time on my hands...

The symptom with the x-axis sounds a lot like what Marlin will do if the endstop switch isn't wired right or connected to the RAMPS electronics board right. The printer starts to move and then goes "Stop! Already at the endstop!", and all you get is a blip of motion. I don't know how the switches are supposed to be wired up on your printer/firmware. Firmware can often be configured for them to work as either normally-open or normally-closed switches. Make sure you've got the x-endstop wires on the right terminals on the electronics board. See if all of your endstop switches are wired the same; one wire should go to a terminal usually marked C (for common). All the switches would usually have the other wire going to the terminals marked the same - NC (normally closed) or NO (normally open).

You could always manually engage the endstop switch and see if that makes a difference on the x-axis being able to move. If it does, you've shown the x-endstop switch is wired/connected different than the firmware is expecting.

If you have the printer connected to host software (Pronterface, Repetier-Host, etc.), you could try sending the printer gcode command M119 and see what response you get. It should return the current state of each of your endstop switches. Resend it multiple times, manually activating and holding each of the endstop switches each time. You should see the M119 responses changing as you activate & release the switches.

BTW - It isn't used much, but there is a subforum here dedicated to the Geeetech printers. You might post future threads in there. Look for it under the Rep Rap grouping. One of the moderators here has a Geeetech.
05-03-2016, 11:29 AM
SLCPUNK

Quote:

Originally Posted by printbus

I've simply seen a lot on my printer and on the printers I've helped others with, and usually have some spare time on my hands...

The symptom with the x-axis sounds a lot like what Marlin will do if the endstop switch isn't wired right or connected to the RAMPS electronics board right. The printer starts to move and then goes "Stop! Already at the endstop!", and all you get is a blip of motion. I don't know how the switches are supposed to be wired up on your printer/firmware. Firmware can often be configured for them to work as either normally-open or normally-closed switches. See if all of your endstop switches are wired the same, and then make sure you've got the x-endstop wires on the right terminals on the electronics board.

You could always manually engage the endstop switch and see if that makes a difference on the x-axis being able to move. If you have the printer connected to host software (Pronterface, Repetier-Host, etc.), you could try sending the printer gcode command M119 and see what response you get. It should return the current state of each of your endstop switches. Resend it multiple times, manually activating each of the endstop switches and make sure that you see changes occurring in the M119 responses.

Awesome. I'll give that a try. Thanks again.

Quote:

Originally Posted by printbus

BTW - It isn't used much, but there is a subforum here dedicated to the Geeetech printers. You might post future threads in there. Look for it under the Rep Rap grouping. One of the moderators here has a Geeetech.

I saw that forum, but there were only two posts, so I was a bit worried it wouldn't get noticed. I'll post future items there though.