My 2009 iMac's internal mic doesn't seem to work anymore. I don't hear it through the speakers and applications that utilize it, like Photo Booth, no longer capture sound. When I move the internal mic slider in system preferences, occasionally the blue-colored level indicator lights up, but it seem haphazzard and not in relation to ambient noise. Should Hardware Test identify a broken mic, because I ran it and it reported that nothing was wrong with my system (hardware-wise). I'm trying to discern whether this is more likely a hardware or a software issue. The last time I used it is before I took it up to an Apple store to have a dead video card replaced and I'm wondering whether it could be a disconnected wire, etc. from that. Would Hardware test know? Any other suggestions for this problem? Thanks.