Newbie ground problem!

[HD28V]

Hello everyone, I am 42 years old and have just become addicted to building effects. I have played guitar since I was twenty, but until about 3 weeks ago had never ventured into building my own stompboxes.
I just completed, well... almost completed my first full build (after a few weeks of learning to read schematics, basic circuitry, practice fuzzfaces, etc) 
I have a question that I'm sure is pretty simple, but since I am an idiot, I haven't figured it out yet.
The fuzzface that I have just finished works perfectly......until I mount it in its metal box. As soon as either input/output jack touches the box it shuts off. I know it has to be a ground problem somewhere, but as I stated, I am a complete newbie. All my joints seem to be fine; everything that is supposed to go to ground is grounded, or at least appears to be.
Any insight will be greatly appreciated. I also apologize if I posted this in the wrong place. Great site by the way.   

[alparent]

Pictures of your build.....schematic you are using.....is it a positive ground FF?
The more you give us....the more we can help.

Welcome to the madness!

[HD28V]

Thank you for the reply.
The schematic came from Muzique.com, I added a tone stack off of the collector of Q2. It's not positive ground.  I am at work at the moment but will try to post a picture of my board if it's not too late when I get home.
http://www.muzique.com/schem/fuzzface3.gif

[StereoKills]

Are you using a metal power jack or a plastic one?

[HD28V]

They are metal.
Sorry for delay, I don't have internet service where I live, I have to wait until I get to work everyday to post or surf.

[deadastronaut]

They are metal.

there's ya problem....get plastic ones!..it'll work fine then..

don't use these..
http://www.maplin.co.uk/2.1mm-single-hole-fixing-dcsocket-1407

use these..
http://www.google.co.uk/imgres?q=dc+sockets&um=1&hl=en&safe=off&sa=N&tbm=isch&tbnid=BmauYhkwxUl1fM:&imgrefurl=http://www.bitsbox.co.uk/connects.html&docid=YN09sUW7663yeM&imgurl=http://www.bitsbox.co.uk/images/connect/dc_boss.jpg&w=242&h=220&ei=6lfnTp-ZBcbQsgbWrMSqBw&zoom=1&iact=rc&dur=514&sig=109562430364659023161&page=4&tbnh=134&tbnw=147&start=146&ndsp=50&ved=1t:429,r:41,s:146&tx=75&ty=83&biw=1888&bih=956

or these  cn125

http://www.bitsbox.co.uk/connects.html

[StereoKills]

Yep, with metal power jacks, you have V+ connected to the chassis, exactly where you don't want it. Always use plastic power jacks.

[deadastronaut]

^ i did this too when i started.....your not alone on that!..

[HD28V]

I really, really appreciate the help, thanks for taking time out to help me.  I will pick some up this evening.
Y'all are great!   

[alparent]

And this happens because in effects the outer ring of the DC jack is connected to the + and not the - like the rest of the things on the planet!

[StereoKills]

And this happens because in effects the outer ring of the DC jack is connected to the + and not the - like the rest of the things on the planet!

I always wondered the reasoning for this. Most things are center positive for just this reason, so that the sleeve can be grounded to the chassis. Stompboxes is the only branch of electronics I've seen yet that does this backwards!

[DavenPaget]

 Checking ma power supplies ... ( These are just some random wall warts , none are designed for the stuff we do )
3 x 12VDC warts , center positive .
4 x 9VDC warts , 2 x center positive , 2x center negative .
Not everything is center positive it seems .

I always wondered the reasoning for this. Most things are center positive for just this reason, so that the sleeve can be grounded to the chassis. Stompboxes and Telephones is the only branch of electronics I've seen yet that does this backwards!

[egasimus]

The jack is backwards so that the switching contact can be connected to the battery IIRC.

If you can't find plastic jacks, though, some rubber washers might do the trick.

[HD28V]

That's one thing that I can check off my list of 33 Kzillion questions! Thanks guys.
NEVER STOP LEARNING!

[StereoKills]

The jack is backwards so that the switching contact can be connected to the battery IIRC.

Yes, but that same switching contact is usually used to do ground switching in center pos circuits. I'm just curious as to why that isn't used more.