Ramps 1.4 board not working.

Hi Guys,

My Ramps 1.4 board is not working when I try to power up from the 12V power supply, but it only works when I power up from the USB. I have measured the voltage at VCC and i'm getting 2.45V not 5V. Does anyone know what is wrong with the board?

Thanks

Not a lot info to go on, with fault finding, are you p
owering the arduino through the ramps board if so is the D1 " diode" installed.

Yes, D1 " diode" is installed. When I power the Ramps 1.4 through arduino it works, however Ramps 1.4 and arduino board doesn't work when I power-up through the 12V (Ramps 1.4 input voltage) Also i get 2.45C at VCC pin next to the 5V and PS-ON pins).
Thanks jinx

Is probably not the ramps but the mega. Unplug the ramps from the mega, and put 12v into the mega dc power jack. I suspect you will still see your 2.45 volts on the 5v lines.

The cause.

The mega has a voltage regulator see top left of diagram [arduino.cc]

The ncp1117, its a 3 pin device, 3 legs on one side and a big tab on the other. Normally just above the power socket.

These can get damaged... a common cause is shorting +5 to gnd

They are surface mount but quite large and easy to replace if you can solder.

Edited 3 time(s). Last edit at 08/24/2014 07:27AM by Dust.