Facing TV Problems? Ask a TV Technician.
Hello, Can you please tell me exactly what the TV does when you press power- does the power light change? Any click sounds? Does the screen light up- even for a second?
Also what prompted you to replace the Mainboard for this problem?
Okay, so you replaced capacitors on the original Mainboard? It's usually the power supply board that the caps fails on.
Regarding the DirecTv box- that has nothing to do with the TV.
When you press power on the TV, does the screen "backlight" at all please? I you grab the Vizio remote and press MENU, does the MENU show up?