Chosen Solution
I have a Vizio M43-C1 that worked fine for 4 years but today the picture went out. No backlight, no picture from flashlight test. However, the sound works. What do you think it is? I got a main board replacement for cheap and that is being shipped to me. If that doesn’t fix it, what else would be the culprit? Thank you. Update (08/29/2019) I replaced the main board and it is fixed now.
@mmpbc4lw check your power board outputs as well. Use the values as printed on the board to verify you have all the proper power going to the main board. After that you want to check your T-con board since a bad T-con board can also cause a black screen. Check the fuse on it for A. power and B. continuity
