Lexicon Omega, No Signal

i bought a lexicon and as alot of others i had trouble but mine is a bit different.

There is no signal being shown on the omega or the computer. i plug the mic or guitar in with headphones and nothing.

all the gear is good so what is the problem? even if the drivers arent working it should still have a signal and sound.

The crap this is that this is the second one i have bought for i thought the first was bung. so the problem must be at my end.

Has anyone had the same problem or can help