My toshiba 65hm 167 wont come on

If you are refering to the 3 yellow blinks repeated over and over the
boot data is corrupted. Download the firmware update(link below)from Toshiba and unzip the files and folders,copy the unzipped files & folders to a SD card (like a camera uses, don't use bigger than a 2 gig). Unplug the tv and insert the card into the slot hidden behind the cover above the HDMI inputs. Plug in the tv and watch the yellow blinking stop and a solid blue will light when done. Unplug the tv, remove the card,plug in the tv and all will be good.