I’ve purchased a Ramps 1.4 + Arduino mega + heatbed MK2B Bundle from aliexpress and am trying to get it to work. First I used a “Led PSU” which could barely power the setup (it was a weak one, just for testing). Then I took an ATX PSU and did the necessary preparations according to this guide: https://reprap.org/wiki/Choosing_a_Power_Supply_for_your_RepRap . Now I have everything hooked up and am using the +5V 1.0-30A and +12V1 0.5-19A configuration. Problem is, that when I plug it in the RAMPS 1.4 connector, it turns on and everything lights up, but as soon as I want to draw power to heat the heatbed up, it shuts down, the entire PSU. Then after a few minutes, I can turn it back on again, but as soon as I want to draw power again, it immediately turns off. Since my skills with electronics are very limited, I was hoping that any of you could help me troubleshoot my issue and help resolve it.
Many Thanks in advance!
Here are Images of my PSU and the cables I’ve soldered to: