PSU being fried by RAMPS 1.4 ?

Hey Everyone,

New to the 3D print scene. I just built myself a prusa i3 einstein variation. I had it working for a few days. I was in the middle of calibrating my Z-axis when the following shenanigans occurred.

Thanks to me being a nub at electrons/wiring I had one of my exposed fan cables hit an exposed power wire (PSU to Ramps) and i saw a spark. The PSU died. I went and bought a new one. I plugged in the new one. It worked. I managed to get motion on all axis. Extruder/Bed reached target temperatures. Than I go and hit the print button (using pronter) and about 20 secs into it the PSU died on me. I unplugged the PSU from the RAMPS board. Toggled the power switch and the PSU won't turn on again (has a fan that I can see when it's on).

To even further complicate the situation, I noticed that my X-axis motor didn't have enough slack on the wires and it pulled some wires out of the motor. Not enough to stop the motor from working, but enough to expose the metal in the wires. Yes, the exposed wires were touching when I noticed it. Keep in mind I had 0 problems with the x-axis motion for the days that the machine was printing.

I am now in the process of trying to figure out what the problem is and what the best solution would be:

a) Is the RAMPS 1.4 board defective and killing the PSU? Is there a way to test just the board?

b) Is the motor frying my PSU?

c) Did I just buy a shitty PSU, was the cheapest memory express had. Cooler Master Extreme II 525W Power Supply.

c) Could it be firmware related? Using a beta version of Marlin. I was changing a variable in the configuration.h file (#define D EFAULT_AXIS_STEPS_PER_UNIT {80,80,4000,252} // default steps per unit

EDIT: I am able to upload new firmware to the Board.

I'm hoping to avoid having to go and buy my 3rd PSU, a new Board, and a new motor

Thanks for reading the long post and for your input

Edited 1 time(s). Last edit at 08/19/2013 11:29PM by doomstrike.

What are the specs on the PSU.

It needs to deliver about 15-16 amps. If it can't deliver that, and you don't have some sort of fuse protection, then yes you can fry the PSU.

Check the link I provided for specs. The original worked for a good 3 days and only died after my screw up.

I followed this wiring guide. 2 pins where 4 wires were twisted together and the other 2 had 3 wires twisted together.

Edit: Oops forgot link: http://78.47.92.212/i3_documentation_pics/09-wiring.md.html

Edited 1 time(s). Last edit at 08/20/2013 02:00AM by doomstrike.

I saw no specs for the PSU. But this link makes me think you got your PSU as part if a kit. If that's the case, I'd go straight to the vendor.

The specs are at the bottom of the page I linked in my post. Lets try a different approach. I will be buying a new PSU. Which one would you guys recommend from http://www.memoryexpress.com/ ? Let's go with a modular one.

doomstrike Wrote:
-------------------------------------------------------
> Check the link I provided for specs. The original
> worked for a good 3 days and only died after my
> screw up.
>
> I followed this wiring guide. 2 pins where 4 wires
> were twisted together and the other 2 had 3 wires
> twisted together.
>
> Edit: Oops forgot link:
> [url=http://78.47.92.212/i3_documentation_pics/09-
> wiring.md.html]http://78.47.92.212/i3_documentatio
> n_pics/09-wiring.md.html[/url]


The instructions to convert the power supply don't look complete. I've done a conversion myself and I've overloaded and shorted mine a few times without destroying the power supply.

The information below shows an example of a more complete picture of what is involved in a PSU conversion.
[url]http://youtu.be/z2oSFpKh_Uw[/url]
[url]http://jumperone.com/2012/12/converting-atx-power-supply-to-bench-power-supply-faq/[/url]

Edited 1 time(s). Last edit at 08/21/2013 09:03AM by Airtripper.