I just received a used set of Paradigm Micros from Ebay and one of the woofers has no sound coming from it. No problem I thought.... I'll just unscrew all the back panel screws and take the back off to see if something had come undone... The problem is that the back won't come off when I try to open it without ruining the adjoining sides of the case. Am I missing something? I know there is no entry through the front as the grills are not removeable. Does the piece holding the speaker posts come off? I could use some help. Thanks!