1 Topic by Chris

  • Chris
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  • From: Acworth, GA
  • Registered: 2012-09-27
  • Posts: 8

Topic: Supernight power supply liberates magic smoke from stepper drivers.

Well, that's just disappointing.
Here I am, all excited to replace the barely adequate and stupid hacked computer power supply on my trusty SD2 with the shiny, highly-recommended Supernight, and the ungrateful little whelp belches smoke and fire from its X and Z drivers.

Salient points:

Nothing was changed from current working setup.

I metered the output and got 12V. Granted, it was with the cheap RatShack analog meter I've had since I was a wee lad, but I double checked with my badass Amprobe and got no spikes on powerup. I have since sat and tweaked the VREF to a solid 12.00V.

Figuring the damage was done, I flipped the leads in case I had connected backwards. Same sizzle.

No scorch marks on the board anywhere. All damage seems to have been localized to the two drivers.

Only upgrades are my beloved E3D-V6 hotend, otherwise all stock. The hackjob power supply was fitted to better accommodate that. It's been working more or less flawlessly, but I figured some more oomph couldn't hurt. Foolish me.

It's got the old Sang board, and I've already gotten four replacement drivers from Panelolu.

It's relatively old. I'm serial 2399.

I had not yet bonded all the + and - terminals together. Logically, that should make no difference unless I need the capacity. I will, I just didn't for my smoke test....which actually provided smoke.

----

I'm really not seeing what went wrong, and not having a whole lot of luck searching about for similar problems.

So my main question is: should I go ahead and plug in my two new drivers, burn some ABS in an offering to Prin-Tor, switch on and hope for the best? 

The moral of the story is to finish your current little project before you make any changes. It's probably less frustrating that way.

2 Reply by dubbsd

  • dubbsd
  • dubbsd
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  • From: Northwest florida
  • Registered: 2012-09-30
  • Posts: 748

Re: Supernight power supply liberates magic smoke from stepper drivers.

I have burnt more than 1 board because I did't catch something
and was told by an electrical engineer

Murphy's law: Anything that can go wrong, will go wrong.
so I now do a double check and if possible have someone else double check.

Ultimaker S3.

3 Reply by elmoret

  • elmoret
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  • Registered: 2012-10-11
  • Posts: 6,048

Re: Supernight power supply liberates magic smoke from stepper drivers.

Sure you didn't reverse polarity?

Filastruder - the robust, inexpensive filament extruder
E3Dv6 All Metal Hotend - the premier 3D printing hotend

4 Reply by wardjr

  • wardjr
  • wardjr
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  • Registered: 2013-06-10
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Re: Supernight power supply liberates magic smoke from stepper drivers.

I am with elmoret on this one.  The only thing that would cause what you've described is reversed polarity or some other dead short to the board like if the board is touching the frame of your printer.

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5 Reply by Chris

  • Chris
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  • From: Acworth, GA
  • Registered: 2012-09-27
  • Posts: 8

Re: Supernight power supply liberates magic smoke from stepper drivers.

Yeah, I'm an idiot.

It was late, and I wasn't paying as close attention as I should have been.  I seem to remember the cord flipping about and squinting at the screw terminals in a vague attempt to reverify polarity.

I just needled it, and on the old supply my negs are on the left side. Oops. So much for having used that as a reference. I don't know what the hell I was thinking when I did that.

And since the chip was already breached, it's gonna smoke no matter what.

See? A couple years of relatively trouble free operation lulls one into a false sense of security.

That's the confirmation I needed. Everything else looks solid, just trying to figure out where I screwed up so I don't do it again.  Time for solder!

Hey kids! When you repurpose a power supply from an Israeli lighting console, label the damn terminals for future reference!