Buzz in a EP Booster build

[Telekaster]

I just finished a Xotic EP Booster ( http://tagboardeffects.blogspot.se/2012/02/xotic-ep-booster.html )
This is my second; the first I built to a friend and it works fine but on this one there is a loud buzz when I hook it up.
I first noticed something was wrong because the pilot lamp kind of flashed when I pressed the footswitch, and then faint to just a weak light, not at all as bright as it should be. There was no sound and no buzz, so I clipped the +wire to the LED and then it works but there is this buzz all the time.
I have checked all the groundings but I can't find anything. When I put back the +wire to the LED the buzz goes away but the effect doesn't work then. When I remove the wire again, the buzzing is not there immediately, but it "fades in" after 3-5 seconds. Can it be a elyt cap that is damaged?

[robthequiet]

Welcome, Telekaster.

I would check to make sure your trace cuts are nice and clean. Also, there could be a wiring issue with the power supply jack. If you like, you could post photos of your build so we could take a look.

[Telekaster]

Welcome, Telekaster.

I would check to make sure your trace cuts are nice and clean. Also, there could be a wiring issue with the power supply jack. If you like, you could post photos of your build so we could take a look.

I have checked the back of the board with a loupe and it looks clean with no solder between the traces.
The strange thing is the LED just light up for a very short moment, then it goes out.  - I suspect it is something on the board that "eats" current
Also the thing that the buzzing comes like "fading in" when switching on. Like it's a cap that gets charged.
It is really annoying, and I don't have any clue how to find the culprit on the board.
Don't know what could be wrong with the power supply jack; I have connected it the usual way.

Image showing the way I do the off board wiring.




EDIT: Problem solved! Had to put a wire from negative on power jack to ground at output jack, it's not working with just a wire from negative to one of the ground points on the board, and the other ground point to ground at output as shown in image.

[robthequiet]

Well, that was easy 

Yes, it sounds like some part of the circuit wasn't quite complete, so one of the capacitors ate the current until it charged up. Good to make a note of this one.