VIZIO 791.00910.0001 MAIN BOARD FOR M552i-B2. This board is fully tested and removed from a set with a defective panel. First, you as the purchaser of the part is accepting the role of the technician in properly diagnosing and installing the part. We do not know your qualifications as such. Secondly, each part we sell came from a TV that had a broken or defective LCD or Plasma panel. Any questionable boards are disposed of.