Hi!

When the Arduino with Marlins FW is USB attached with no ramps. Repetier can connect to the Mega. I have the RAMPS 1.4 connected with 4 a4988s the Jhead hot end, and an LCD+SD+ Rotary encoder. But when it is connected to the arduino, My COM5 is not showing up.

I don't know if it is a problem, but when the Ramps is connected the little I'm guessing voltage regulator next to the DC plug on the mega is very warm. Right now with just the Arduino, Com5 ARDUINO is showing up and I can connect with Rep. That little chip is not warm at all.

The ramps was tested with just the jhead/and 4 motors fine before.

I never got the LCD/SD thing running. I'll try removing it.

Should the board below that power regulator on the arduino be warm?

I do not have that diode installed.

Any ideas?

PS I have an Xbox 360 203W powersupply.

Smells to me it is the same problem, look here [forums.reprap.org]