I just bought a 12" i3v and am having some issues powering it with a PSU. It's the 12v 30 amp PSU from Amazon. Here's a link:

http://www.amazon.com/Universal-Regu.../dp/B00D7CWSCG

I've wired a power cable to the PSU and when it's on it shows the expected 12v from all of the +v and -v outputs. However, under any load the voltage drops to 2-3v. Even powering just the little fan that comes with the e3d v6 hotend the voltage drops to this level. This voltage drop also occurrs when the PSU is wired to the 5 amp rail on the RAMPS board. The D1 diode is soldered in so that's not the issue. When the PSU is wired to the 11 amp rail however, the voltage does not drop, but I suspect that is because there is no load on that rail. I get these same results with nothing plugged into the RAMPS too. Do you guys have any idea what the issue might be? The PSU is set to 110v as it should be. Let me know if you have any suggestions.

Thanks,

Preston