Acoustic/Electric Amp trouble

I am having trouble with my Behringer Ultracoutic AT108 I just purchased. I have a Epiphone Hummingbird acoustic/electric. When I plugged it

up to the amp I got scratching and popping sounds. I have a lava Blue Demon cable that I use to connect. Every time I try to play through the

amp I get those scratching and popping noises from the amp. My guitar has a Shadow preamp. Nanoflex pickups.

Any help would be greatly appreciated!

Armando

Ok. "20 questions" time.
Note: Jack could be the Jack on the amp or guitar.

Does the amp do the same thing when you don't have anything plugged in?
Yes = take the amp to the shop, no = go to next question.

Does it happen only when you turn the volume or tone knobs? Yes = bad pots, replace them. no = go to next question.

Try a new cable. Do you get the same thing? No = probably a bad cable. Most likely bad solder joint at the jack. repair or replace. Yes = go to next question.

Does the cable seat firmly with an audible "click?" No = probably a bad jack, replace it. Yes = go to next question.

Does it go away if you hold the cable in certain positions? Yes (assuming you still have the new cable plugged in) = probably a bad solder joint on the wires to the jack. re-solder the connections.