I just purchased a brand new arduino mega.
I think it's defective when I plug in the arduino mega with either a usb or power plug it will not power up.
What could be causing this?
Is the power on? Check it with a multimeter On the board check the voltage on the regulator .The regulator might have been shorted out. On the chip check the voltage on AREF and AVcc. Check the ground connections ,ground on the chip back to ground on the regulator. etc