A12 works with Dynamic mics but not condensers

[jlearman]

A few months ago I put together an N72 and an A12, the N72 works great...love it. But, I'm having the following issues with my A12:

1) If I plug an sm57 into it, it works fine.
2) If I plug in a phantom-powered condenser mic, it only works if my finger is touching a non-painted area of the chassis.
3) If I use my ADK TC Tube mic (has an external power supply) I get a crazy amount of loud noise...as in so much noise that it redlines the meter in my 002.

Obviously there's something going on with the ground or phantom power, but I have no idea where to start trouble shooting. Would love your input!

Thanks,
Joe

[tpryan]

It sounds like the cable shield isn't grounded. Check the jumper at J3. Check soldering at CONN1, pin 1, J3, and J7, pin 6. Make sure the wire harness is making a good connection to J7, pin 6.

[jlearman]

it was the jumper at j3. Many thanks Tim!