NAD 208 troubleshooting

I know this is going to make my sound like an idiot but here it goes. I was installing a new crossover into my subwoofer but I didn't quite know how to make all of the connections. What I did was I plugged one end into my Nad and began testing diffrent wire variations till I got the correct frequencies. I thought this would do no harm. I think I was wrong. One wrong wire variation caused the red powering up/powering down light to come on. That had never happened before. After I realized this wasnt a good test method I stopped to make sure my nad poweramp was ok. What seems to be occuring after this mistake is this...

- a lot of faint distortion in the speakers when there is no signal.
- same distortion seems to increase when I touch the power amp chassis.
- this last may be just me being paranoid but it seems to hum louder than it use to.

I'm not really sure what to do about the distortion. Is this a major or minor problem? Does anything need to be replaced? Has anyone made a similar mistake? Any feedback would be greatly appreciated.