Power Supply I am confused

Hey I am a bit confused with powering RAMPS 1.4, coudn't find clear answer for me yet.

I am using RAMPS 1.4 to control my CNCmachine, before I start to test out all stepper motors I need to be sure I understand it correctly. I want to test it with pronterface, so I need to have my USB cable pluged, it means I power my RAMPS with USB(I need connection with PC to control by pronterface) , but I need to Supply 12V for Stepper motors. If I have diode D1 and D2 soldered is it safe?


"Power Supply with diode
If your board has a 1N4004 diode soldered in, do not apply more than 12 V to it" --< 12V from Power supply + USB supply Is it ok?

Yes it just means don't connect more than 12V to the 12V supply rails if you have the diode fitted.

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[www.hydraraptor.blogspot.com]

The RAMPS board will power the Arduino if you have D2 soldered in place. If this is the case, do not exceed 12V on the PSU that you connect to the 5A connector or you may fry the Arduino. If you want to power the steppers with more voltage - some people do - The RAMPS handles it just fine, just do not install (or remove) D2.