Leaky keg...post or disconnect?

I have a new-to-me keg that came rebuilt from Adventures in HomeBrewing. I have a new disconnect (ball lock to MFL) from my LHBS. The keg help pressure in shipping. I filled it last night and tonight when I hooked up the beer line, I'm leaking.
I'm doing a test tonight...leaving it pressured up (no CO2 or beer line) and see if the top is wet. In the morning, I'll test the beer disconnect on another keg. Anyone ever had a bad out of the box disconnect?
Any other ideas?

Use some soapy water (dish soap works great) and apply around possible problem areas. when you find bubbles, you found a problem.

You need to be a little more specific. Where are you leaking? Are you leaking beer or CO2?

It's not unheard of for a new QD to leak, but a more likely source is the post o-ring. Do the o-rings look fresh? I'd try applying some keg lube to them.

I was leaking beer. I shifted to a different beer line/disconnect that was pretty well keg-lubed up from the other keg and that cleared it up.
Add me for "use keg lube"
Thanks