Zenith 3000 Power Jack issue

[mcdmgb]

I have been slowly repairing a Zenith Trans Oceanic 3000-1 radio that was dead when I got it. I am in the home stretch of putting it back together, but have run into an odd problem. When I reattach the 12-volt power jack to the chassis and use the wall wart, the radio is dead. If I have the jack loose and hanging, it works fine with the wall wart. It appears to be some sort of grounding issue, but I'm not sure what I need to do.

Anyone run into this before?

Thanks