Stepper Controller Board not working?

Hello all,

I have been trying to get a repstrap up and running for what seems life forever. It seems that the closer I get the more issues pop up.

I got 3 of the 2.3 stepper controllers from MakerBot and tried to hook them up. I will admit I am not the most careful with circuits (I am actually a mechanical engineer, dont know why I try to do electronics), but at the same time I do take precautions not to fry stuff.

Anyway, I have 3 boards and they are hooked up to my motors, and I am running them off of an old pc using a printer port. Now I hooked one up and everything worked perfectly, I am using only 3 of the pins on the ribbon cable that would normally go to the reprap mother board. these pins are ground, step, and direction. everything else is left unconnected. (I know, not the best practice)

Then I hooked up a second one, and it worked for one night. A few days later I attempted to hook up the third one. Things must have been moved or fiddled with, because I can only get the very first board to work.

Things i know:
*all the motors are fine, because I have interchanged them with the working board.
*the connections to my pc are fine, because I can interchange them with the board.

I don't see how i could have misconnected power, because the molex connector is keyed.

When I connect the power, the power led lights up, but I do not get any other leds light up for the motor coils like my working board does. the motor does not jump to life. I get no response from sending step signals, nor direction changes. Also the power led get dimmer as time goes on. if i disconnect the interface pins (step, direction, ground) the led get brighter again. Also the ic might be getting a little hotter then the other one, but it doesn't seem to be getting overly hot. nothing else seems hot.

Worst of all makerbot is out of assembled boards. This leaves me with a few options

1. wait for new boards,
2. get an older controller board kit, version 1.2
3. try to figure out what is wrong, and possibly swap out the ic or other fired part on the boards.

Any advice? Anyone have some 2.3 assembled boards I can buy?

thank you in advance,
Josh

Sounds like you have left the enable lines floating. You need to tie it low or connect it to an output on your parallel port.

If you connect or disconnect the motor with the power on (or have a loose connection) you may have damaged the driver chip.

---

[www.hydraraptor.blogspot.com]

Hi Josh,


First mark the boards to Identify them if you havent done this alredy.

Before adding your enable wires you should also check that position of R1 the curent setting resistor is in the same position as R1 on the working board.


If the above still fails to fix the problem.

If you can remember which one of the two non working ones worked.

Then It would be worth examining that board with a magnifing glass looking for a bad/lose solder joint.

---

Bodge It [reprap.org]
=======================================

---

BIQ Sanguinololu SD LCD board	BIQ Stepcon	BIQ Opto Endstop
BIQ Heater Block PCB	BIQ Extruder Peek clamp replacement	BIQ Huxley Seedling
BIQ Sanguinololu mounting	BIQ standalone Sanguinololu or Ramps mounting	Print It Stick It Cut it

My rep strap: [repstrapbertha.blogspot.com]

Buy the bits from B&Q pipestrap [diyrepstrap.blogspot.com]
How to Build a Darwin without any Rep Rap Parts [repstrapdarwin.blogspot.com]
Web Site [www.takeaway3dtech.com]

Thanks for the quick response guys. I will try both of those suggestions tonight when I get home. Hopefully just the something simple.

Josh

Well, I just got home and was hoping the enable bit would fix the problem. But no luck. I was not able to get any response to using it. I connected the working board and tested that I could still move the motor. everything works fines, then I connected the enable bit to one of my other outputs and attempted to toggle it to enable and disable the motor. But nothing changed.

Then out of pure hope I tried to do the same for the non-working boards, but still nothing happens. I did however notice that when nothing is connected to the interface the driver chip remained cool, but once I connected my interface plug the chip got hot, so I unplugged everything immediately.

The fact that the chip get hot leads me to believe that I must have fried it. (I should have been smarted then that).

What do you guys think? while I wait I am gonna go read about surface mount soldering. lol

Josh

I have 6 2.3 stepper controllers built and connected to two machines.

I have used the enable pin on all of them to prevent my motors getting too hot when not being used.

Look here for the full connection info.

Im not sure why you are not seeing the effect of the enable pin on your working board thou.

---

Bodge It [reprap.org]
=======================================

---

BIQ Sanguinololu SD LCD board	BIQ Stepcon	BIQ Opto Endstop
BIQ Heater Block PCB	BIQ Extruder Peek clamp replacement	BIQ Huxley Seedling
BIQ Sanguinololu mounting	BIQ standalone Sanguinololu or Ramps mounting	Print It Stick It Cut it

My rep strap: [repstrapbertha.blogspot.com]

Buy the bits from B&Q pipestrap [diyrepstrap.blogspot.com]
How to Build a Darwin without any Rep Rap Parts [repstrapdarwin.blogspot.com]
Web Site [www.takeaway3dtech.com]

sounds like ESD to me.

just touching the digital inputs with fingers can destroy the chips from electrostatic discharge.. they can only withstand up to 200v discharge maybe once, but we don't feel it until about 10,000v!

I was out of the country for a week and just got home to about figuring out what I messed up. I had ordered replacement driver chips before I left.

I got back and swapped out the ICs on the board with the new ones, and presto they work again. It was a little difficult to remove the old chips, but I got it to work.

So basically, somehow I must have ruined those chips. It was about a 12 dollar, and 8 hour mistake.

I figured I would post how I got them working again, so that if someone else actually reads through this looking for help they can have some conclusion.

Josh

Anyone know what parts he replaced,exactly? Is it this part?

[www.mouser.com]

That's the voltage regulator that provides 5V from the 12V supply. That would be the chip to replace if you can't find 5V on any of that chip's pins when your board is powered.

If the 5V regulator is working then it is probably the stepper driver chip that failed.