Power on nothing happens....

[Cameron]

OK So I loaded firmware onto my ramps board and that seemed OK. I then mounted the circuit board to my i3v and attached all the wiring.
When I flip the power on my power supply, nothing happens.

I double checked that my power supply is providing about 12.4V to both the 5amp and 11amp connectors.

I know that the 12V is getting to the board, but I don't know what to do now... No lights no display.

Any help would be greatly appreciated.

[printbus]

It could be there's a short somewhere in your wiring, and either the 5V power circuitry or one of the resettable fuses on RAMPS is preventing the short from melting or burning something.

If you have RAMPS all connected to the servos, end stop switches, etc., I'd start by unplugging everything from it except the power wires. There's a green LED on RAMPS that should flash when the MEGA2560 firmware starts executing - use that as a 5V indicator. If that works, plug in the LCD. The point here is to get the RAMPS configuration down to a minimum that hopefully does work, and then slowly add connections to it one by one to see if that reveals a connection that is a problem.

Make sure, for example, that the endstop switches are connected properly. Connected wrong, they can short +5 to Ground - leading to the symptom you have. Installing the endstop connectors on the wrong pair of pins is easy to do.

[Cameron]

Yeah I yanked all the connectors and it powered up.
So then I installed each one again and checked.
Now it all works. Thanks for the advice. My guess it was one of the end-stops, but hard to say.

[printbus]

Glad to hear you're farther along now. I agree it was likely one or more of the endstop switches. Don't feel bad. It wouldn't be the first time someone has plugged them onto RAMPS wrong, and it won't be the last.