Fried Board??

Admin note: I apologize for the double post. The first one said I looked like a spammer. Didn't realize it posted. Guess there's no way to delete!


Hello-

I ran into a situation last night that I need some help with. I was working on tuning my stepper motors on my 2020 Prusa i3. Using the information provided here, Adjusting stepper current, I was able to make my steppers run incredibly quietly with barely any heat build up. I printed a job that took about two hours and it ran great.

Not being one to leave well enough alone, I found a video on speeding up the printer. This involved doing resonance testing and isolating and testing acceleration speeds (Tuning Speeds). Close to the end of one of these tests, the printer stopped running. I also noticed that my 2004 display only displayed white squares. To top it off, I also noticed that my laptop had shutdown. After unplugging the printer from the wall I restarted my laptop and reconnected it to the printer via usb. The display came on normally. As soon as I plug in the printer to the wall however, my laptop shuts down and my display goes back to white squares.

Any ideas? From what I've been able to glean from similar posts, sounds like I fried a board. Any tips on how to isolate the failure would be appreciated. I'd like to think this was bound to happen at some point and I just found an existing issue rather than my curiosity killed the printer!! LOL!

Thanks in advance!
'hack

Edited 1 time(s). Last edit at 01/03/2017 08:09PM by DynamiteHack.

You are probably sending 12v back down the USB cable to your laptop USB port.
I would bin everything and start fresh with a new Arduino and RAMPs combo - cheap enough off ebay or AliExpress, though I like the StaticBoards RAMPs more than the clones from China.

Steve

Thanks for the response, Steve.

After searching the web I stumbled across someone else that had this issue. He attributed it to a bad stepper motor driver. Seeing how I was messing with those last night, I decided to try swapping the unused E1 driver with each used driver to see if I could isolate the bad one. On the third try I was able to power up the contol boards and connect to my laptop without shutting it down. Unfortunately, my laptop doesn't recognize the Arduino anymore. Not sure why that would be...thoughts??

It seems, your steppers have sent some back EMC through the drivers into the arduino and fried it. When you move the X-or Y-axis manually, the display magically starts to light up. Do this to fast and your board is toast.
Also important is to feed the laptop and the printer PSU from the same wall plug to avoid ground loop issues.

Quote
o_lampe
It seems, your steppers have sent some back EMC through the drivers into the arduino and fried it. When you move the X-or Y-axis manually, the display magically starts to light up. Do this to fast and your board is toast.
Also important is to feed the laptop and the printer PSU from the same wall plug to avoid ground loop issues.

So, you would agree it seems that the arduino is probably bad? I have an Uno that works fine on my laptop.
Wonder if I should replace the stepper drivers also?? I would hate to replace the arduino and fry it again. I am not sure how to determine the cause of the problem...

Guess I'll take Steves advice and replace both boards.

Thanks for the response!!