NO SOUND / PIC ON MY LG PLASMA

[CONFUSED+GUTTED]

CAN ANYONE HELP ME PLEEEEEEEEEEEEEEEEEEEEZ!
MY 2ND HAND LG PLASMA ALL OF A SUDDEN WENT OFF; FIRST THE PIC WENT, THEN AFTER I FIDDLED WITH THE SCART LEADS IN MY VM BOX THE SOUND WENT ASWELL!!! ITS BEEN LIKE THIS FOR OVER 2 WEEKS AND ITS DRIVING ME MAD! WHEN I SWITCH IT ON I HEAR A V.LOW BUZZZZ AND SOME RED LIGHTS COME ON AND THE SND/BY LIGHT CHANGES FROM RED TO GREEN..................BUT NO PIC ARRRRRRRRRRRGHHHHHHH!