It is not unusual that something is wrong with a new Stagg. Don't loose too much time trying to correct it, better show the dealer the problem and let him get a new one for you.
You won't get any output if the battery is not connected, so there must have been some contact to get a noise. If you open the door of the battery holder and it pops out it usually means that the contacts are well made when the door is closed.
But keep an eye on polarity. I'm not sure if it doesn't work with wrong polarity or even get damaged if you try that. If the polarity is correct give the stagg back and explain/show what's wrong with this one and that you paid for a working one.
BTW, some of the Staggs come with damaged or noisy electronics. A good reason to give such an instrument back.
If you got it really cheap and damaged you might want to remove the electronics completely and connect the piezo wire directly to the output jack, but then you might need an external high-impedance preamp, depending on your amp.
And read through the Stagg EUB megathread where your question might belong...
Last edited by DoubleMIDI : 01-14-2014 at 03:17 AM.