Tascam 414 mic/line noise

[jac.pic]

So when I plug a mic into the front of my Tascam 414, any four of the tracks, I hear loud this hum in my monitors. Think of when you plug a guitar cable into the amp and have the 1/4 end laying on the floor.
This noise is even louder when I use phantom power.

What could be wrong? Could anyone suggest a fix ?

 

[jac.pic]

***Update***
I tried plugging my guitar into the Tascam and everything sounds crystal clear.
Also tested the mics I'm using on an interface and got problems as well.
What I'm using is an XLR to 1/4". It sounds like it's leaking power, but when I used the regular guitar cable it was fine.
What kind of cable do I need to plug a mic into the front of this thing?

 

[A Reel Person]

...

Are you using an XLR-1/4" cable that just shunts the 3rd pin to ground, or an XLR-1/4" transformer adapter?
The cable is suspect. The transformer adapter is recommended.

 

[jac.pic]

I figured out the issue.
I've been using an XLR to TRS 1/4".
I tried an XLR to TS 1/4" and it worked great.

 

[A Reel Person]

Thanks Dude Good Luck!

The 414's 1/4" inputs are unbalanced, TS jacks.
A mismatch like that will do it every time!