The TV is a Vizio D55U-D1. The screen will not come on, but the white LED indicator does come on. It lights up, fades, sometimes blinks, and eventually turns off. It also sometimes comes back on after a few minutes. The screen always remains blank. I have tested several things inside the TV with a multimeter and have found that the power board is putting out a stable 5v at the standby pin that is connected to the main board. The corresponding pin on the main board also reads 5v. On the same connector, the 3 or 4 pins that are labeled 12v on the legend all read 19v on the multimeter. The only other discrepancy I can find (with my low skills) is the connector that goes from the power board to the LED driver board that is labeled at 24v is only putting out 22v when the TV is switched on. I have already replaced the main board with no change, so I don't think it's that (unless multiple things broke at the same time). Could something busted on the power board have caused the 7v increase and 2v decrease for those pins? And would that cause the TV screen to remain blank? Thank you for any suggestions.