Loud noise when guitar or mic plugged into mbox

[ryanfergusonnz]

Hi,
I running protools LE 8.03 through an Mbox 2 on OSX (10.6.4).

I have an issue with plugging my mic or guitar into the either of the inputs, when I do I get loud white noise. It is coming out of the monitors and registering on the meters.
The mic (rode NT3) is being plugged in with an xlr to guitar jack cable, so not running on the phantom power at all. It seems to happen when I enable the mic/DI button on the back of the mbox. The input controls on the mbox don't seem to make a difference at all.

I switched cables and I get the same thing. Thinking it was the mic I plugged my guitar into the jack and I get the same result, no audio unless I enable the mic/DI switch, at which point I get the extremely loud noise.

I've used the same setup a heap of times before, and had no issues. Thinking it might be cables or interference from bluetooth I have gone through and changed/turned off everything on the mac. Still no joy.

I am downloading the protools software update at the moment, but I am thinking this is a hardware issue. The mbox firmware version is 1.40.

Anybody had the same issue?

Cheers

Ryan