Hi Group, can someone help please? workin on a Vizio E480-B2 no pic, patient said, tv has sound no pic, i experienced neither. when testing psb, i got 5v stby, and 3.3 pwr_on 12v on 3 other pins,.. when test F1 301 no fuse on main board, i get 5v one side of fuse zero volts on other.. any suggestions on this matter will be taken seriously.

On Wednesday, December 2, 2020 at 12:35:40 PM UTC-5, wrote:
Hi Group, can someone help please? workin on a Vizio E480-B2 no pic, patient said, tv has sound no pic, i experienced neither. when testing psb, i got 5v stby, and 3.3 pwr_on 12v on 3 other pins,.. when test F1 301 no fuse on main board, i get 5v one side of fuse zero volts on other.. any suggestions on this matter will be taken seriously.

If you have an open fuse, 99% of the time a fuse isn't going to fix it, unless it's one of those square white ceramic fuses with the metal end caps (those will fail for no good reason). Since there's no schematic for the main board, you're going to need to trace out the circuit by hand. Unfortunately, you may find no direct short off the fuse, but a secondary short on the far side of a buck converter that the fuse feeds, which is harder to trace out. It might also ultimately lead to a shorted BGA chip. You can find a main board that model pretty cheap.

If you have a current limited supply, you can feed a current into the load side of the fuse (maybe 1 amp) and watch what gets hot. If a regulator IC gets hot, the short is probably on the output side of the regulator.