Thanks to phloudernow's suggestion, my gun works again. After popping off the bottom plate from the pistol grip, I saw that the positive wire was loose; put it back in place and the gun fires normally again.
Sorry everyone for me jumping to conclusions; please forgive me as I'm still new to the whole AEG side of airsoft, having only owned cheap Canadian Tire and Walmart spring clearsoft before being able to afford this M15A4 Sportline with all the Christmas money I got during the holidays.
But I want to now ask, am I right that the cylinder on my mechbox is of the unported type? I have a new Madbull Black Python 509mm-length 6.03mm tightbore barrel on its way to me so I'd like to know, as I've heard ported cylinders don't work with long barrels.
My airsoft guns:
Classic Army M15A4 Sportline Rifle (SP003P-1)
Umarex Beretta 92FS Walmart Clearsoft Spring Pistol
Last edited by NS-Airsoft-Noob; January 29th, 2013 at 14:12..