I've got a Realistic DX-390 I've had for about a year now. I misplaced the plug in adapter I had been using and tried a new one. upon doing so there was a "pop" so I immediately removed it. I later found the correct one and plugged it in but now there is no sound. The buttons still "beep" when pressed but no sound comes out of the speaker. I tested the speaker and its not blown. I imagine that "pop" was the sound of something being blown but what? I'm pretty good about soldering/repairing things I jus don't know what to be looking for to replace. any help would be greatly appreciated.