Need help throubleshooting / maybe fixing the controller board

[QtProgrammer]

I have NO IDEA if this is L7 board! If not, please move the topic accordinhgy, thanks!

So I bought my laser from Banggood on Sep 2016.
It worked nicely until couple months ago when it basically sat on my bench for a while and when I tried to do some light lasering wouldn't move motors anymore. So I just said fudge it and ordered EleksMaker Mana SE board and it arrived and everythings fine and dandy. But I have 'half working' controller board and was wondering if I could fix it and use it to build other machine.

Image of the board is attached.

The arduino nano board is working.
1 of the stepper motor controllers was not working as when it was attached to whole board my computer didn't recognize arduino. I changed 'new' controllers and then computer recognizes the arduino. But now the motors won't run and I can't turn on the laser from any software. Weak laser button ligths the laser properly.

So I was wondering if somebody knows what might be wrong with the board and if it's fixable. I can do some soldering but I really don't have any idea how electronics actually work, I just plug things in and most times they work
Also have multimeter so can make some measurements if needed.

EDIT: forgot to attach the image, d'oh!

[Zax]

Are you sure the Nano was plugged in the correct holes?

There is an extra set near the USB end.

[QtProgrammer]

Yes.
I can't connect to nano if I plug in the bad motor controller.
With good motor controllers I can connect to nano but can't move motors or turn on laser.
Motor controllers work elsewhere.

[Zax]

Is it possible the 12V is shorted by a bad MOSFET or capacitor?

The Nano would still work (at least it should) but no motors or laser control.

[QtProgrammer]

I guess it's possible, I really don't know?
Can I test this with multimeter and how would this be done?
As I mentioned I don't know that advanced electronics :|

[Zax]

Measure the voltage at the 12V fan connector, if you get 0VDC or very low it's shorted somewhere - or the power switch is defective. I've heard of that too.

Most likely would be the electrolytic capacitor or MOSFET.

[QtProgrammer]

Weirdest things are happening, but I think we're getting good info here.
So 12V fan connector gives 12.05V  so working OK.
I put the 'new' (four years old, working elsewhere) motor controllers in and tested with the laser.
X and Y motors didn't do jack smith but laser pulse suddenly works (it didn't last time I tried with these.)
I put in the originals for this machine (which are the 'bad' ones or at least one is). No connection to nano.
I put in the ones I got with the new Mana SE board. Y motors work but with X the motors make a sound but do not move.
With new Mana SE board these controllers work flawlessly. I did not try old controllers on this new board.
So there's actually quite a lot working on the old board too. Gonna do more testing...

[rpt007]

Could you solve your problem already?
If not, maybe the current adjustment of the motor driver(s) causes the problems.

I am a bit astonished that apparently there is no information about how to adjust the stepper motor current on the drivers which always should be the very first thing to do when using an A4988 (or the better DRV8825). Pololu has issued some very helpful information about how to set up the current limits - here is the starting point:
https://www.pololu.com/blog/484/video-setting-the-current-limit-on-pololu-stepper-motor-driver-carriers

Before you follow those instructions you should check your motor's max. current (read the stepper motor's datasheet for that information).

Maybe this helps to avoid either killing your motors by burning them with too much current or not moving them by too less current flowing.

[ThothLoki]

Could you solve your problem already?
If not, maybe the current adjustment of the motor driver(s) causes the problems.

I am a bit astonished that apparently there is no information about how to adjust the stepper motor current on the drivers which always should be the very first thing to do when using an A4988 (or the better DRV8825). Pololu has issued some very helpful information about how to set up the current limits - here is the starting point:
https://www.pololu.com/blog/484/video-setting-the-current-limit-on-pololu-stepper-motor-driver-carriers

Before you follow those instructions you should check your motor's max. current (read the stepper motor's datasheet for that information).

Maybe this helps to avoid either killing your motors by burning them with too much current or not moving them by too less current flowing.

Adjusting the stepper motor current has had a sticky thread for some time now. It was posted back in November of 2016
http://benboxlaser.us/index.php/topic,20.0.html

[John Henriksen]

Well a new 3-axe board cost only 30 USD 

[rpt007]

Well a new 3-axe board cost only 30 USD

Well, if you trash 10 of them by not paying attention to the current limit settings it's already 300 bucks.
And: My Murphy's law says: the probability that you trash something gets higher the closer you get to a weekend where you can't quickly buy a replacement ...

[rpt007]

@ThothLoki:

Adjusting the stepper motor current has had a sticky thread

Thanks for the information; as I am just beginning to rush through this forum, I didn't (yet) come across that thread.