Different part/board numbers we service. Symptoms of a bad main board. HDMI ports do not work. The TV is not displaying color on the HDMI ports. Only black and white. TV does not initialize. How does this REPAIR SERVICE work? We process the package once it arrives. Once your board has been fixed, we will test it in a live TV set to ensure quality! We will visually inspect the package and board upon arrival and note down any damage and take pictures if need be. Do you work on boards that have been fixed or reflowed before? We sure do, but you must message us with details prior to placing an order. What if my symptom isn’t one of the symptoms in your listing? We are able to repair symptoms not listed, but you must message us prior to placing an order. What happens if you can’t fix my board? What if you receive my board in working condition and it passes your tests? The item “Mail-in Repair Service For Vizio M3D420SR Main board” is in sale since Monday, March 12, 2018. This item is in the category “Specialty Services\Restoration & Repair\Electronics”. The seller is “nickstvs” and is located in Tucson, Arizona. This item can be shipped worldwide.