I just picked this mic up from a friend of mine who no longer had any use for it. Was told before it was put away the connector was changed from 4 pin Cobra to 5 pin Cobra. This thing has been sitting in a dirty attic for years. The battery connector was barely hanging on. So I threw a new battery in and it was going crazy when i keyed it and squealing. So I changed the battery connector and contact cleaned the heck outta it and put it back together. Now when I turn it up just a little bit and the screen touches or even comes near my face it squeals. You can tell its a screamer on this 29 Im using it on but would like some input before I start troubleshooting. I'm suspecting the plug because everything looked ok inside. Any ideas?