any source is black and white

@ivebaez that is because your icons are part of the firmware which resides in some IC's on your main board. The video you are receiving does not, so this could be a mainboard issue as well as a T-con board. We will need to know what model your TV is, what you have tried i.e. different HDMI cable and if you have checked all of your video inputs. Do not just rely on one, test them all. WE may even need to see your boards to determine if you have an integrated T-con board or a dedicated one. PITA but probably needs to get done :-)

If you can post pictures of your boards Ajout d'images à une question existante

@ivebaez so this most likely is a main board error with your TV. Here is the interesting information. It appears that this is a common error and that the Vizio main board 756TXCCB02K030 is pretty much unavailable. Anytime a series has common issues, you will find that the boards are almost never available. Of course you can try a used board, check Ebay.com etc. for a replacement. There is also the possibility to have your board repair. Check companies like this for that. Cost is about 75% of a new board.