Microphone, What should i do if my microphone does not work, How can i prevent microphone feedback – Sony VGN-NS150J User Manual

V G N - N S 1 0 0 S e r i e s, VGN-NS140E, VGN-NS135E, VGN-NS130E, VGN-NS115N, VGN-NS190J, VGN-NS160E, VGN-NS110E