I bought a ramps 1.4 kit and don't know how to wire the power to it no sites show any specific details on a power source. I have a old atx power supply and I was wondering if I could use that and if so how to properly wire it, also my ultimachine kit came with a 36" 10 wire cable that I'm not sure what its for. https://reprap.org/forum/read.php?219,124192,124192#msg-124192 Tue, 13 Oct 2026 01:09:07 -0400 Phorum 5.2.23 https://reprap.org/forum/read.php?219,124192,129826#msg-129826 https://reprap.org/forum/read.php?219,124192,129826#msg-129826
Anyway, your current PSU should be enough to get you started. Can you verify that the board is being supplied with 12V, and with the correct polarity? If there's a short the PSU may have shut down. The Arduino itself will still run since it can be powered by the USB connection but no heaters or motors will work. If the polarity is reversed, nothing will work. Also double check you're powering the 5A terminals, the 11A set are dedicated to the heated bed. If in doubt, post pictures.]]> Andrew Smith RAMPS Electronics Mon, 23 Apr 2012 08:40:52 -0400 https://reprap.org/forum/read.php?219,124192,129823#msg-129823 https://reprap.org/forum/read.php?219,124192,129823#msg-129823 Thank for response.]]> lukasso RAMPS Electronics Mon, 23 Apr 2012 08:13:34 -0400 https://reprap.org/forum/read.php?219,124192,124710#msg-124710 https://reprap.org/forum/read.php?219,124192,124710#msg-124710 -------------------------------------------------------
> I found a suitible power supply for $20 but while
> I'm waiting for it to arrive can I power it from
> the arduino? If so i doubt I would be able to
> power my heated platform from the ramps

Best case scenario is that it just won't work.

Worst case scenario is that you'll blow your Arduino and / or you RAMPS, because the motors and the heat-bed want several amps total current supply (those 5 amp and 11 amp fuses on the RAMPS are there for a reason!), whereas the Arduino Mega is only rated for a few hundred milliamps total.

You need to wait until you get a proper power supply!]]> julianh72 RAMPS Electronics Sun, 18 Mar 2012 23:42:47 -0400 https://reprap.org/forum/read.php?219,124192,124708#msg-124708 https://reprap.org/forum/read.php?219,124192,124708#msg-124708 aplavins RAMPS Electronics Sun, 18 Mar 2012 22:51:28 -0400 https://reprap.org/forum/read.php?219,124192,124326#msg-124326 https://reprap.org/forum/read.php?219,124192,124326#msg-124326 shinjinian RAMPS Electronics Thu, 15 Mar 2012 21:06:46 -0400 https://reprap.org/forum/read.php?219,124192,124221#msg-124221 https://reprap.org/forum/read.php?219,124192,124221#msg-124221 reprap.org]

Hope this helps!]]> julianh72 RAMPS Electronics Thu, 15 Mar 2012 03:12:33 -0400 https://reprap.org/forum/read.php?219,124192,124192#msg-124192 https://reprap.org/forum/read.php?219,124192,124192#msg-124192 shinjinian RAMPS Electronics Wed, 14 Mar 2012 19:46:16 -0400