Today were going to walk you through a typical LCD TV fix. Today’s TV to be fixed is a 47″ Vizio, Specifically the “VO47LFHDTV10A” model.
Tools: ESD wrist strap, several sizes of magnetic Phillips head screw drivers, pill box or magnetic parts try, replacement circuit boards, volt or multi meter, and a blanket. We prefer not to use power tools on most LCD TV’s due to the ease of stripping out the screw holes on the plastic bezel. If you have a screw gun (NOT a drill) with low torque and your careful, you should still be fine.
The first step is to assess the situation. As you will see most LCD TV’s have a power board and a main board, and usually one or the other has gone wrong. If the TV does not turn on it’s usually the power board, which powers the LCD itself. If the TV turns on, there is sound but the picture is blank, it’s also probably the power board. Now if the TV turns on, you see a picture but lets say HDMI 1 does not work, then it’s more likely the main board, which handles the media input. This TV would not turn on, so we first replaced the power board.
Make sure you unplug the TV first! This TV was on a stand so with an extra set of hands we removed the TV from it’s mount, here we have placed it on a blanket on the floor (to keep the bezel from getting scratched) and are getting ready to remove the back. You can already see the power board (top in beige) and the main board (bottom in green) pretty clearly through the back of the TV.
Now that we have the TV on the floor we can take a closer look at the right side. When fixing an LCD TV you have to remove the back panel, and in this case the mounting brackets also.
The picture is a little blurry but you can see the mounting bracket for the TV stand along with the screws along the outer edge. To remove the screws we recommended using either a pill box and putting the screws in from left to right in the order you take them out, or using a magnetic parts dish and do a similar process. Even though you may be removing screws from the same area, sometimes they can be different sizes.
This is a closer view of the main board, as you can see your HDMI and other connections plug directly into the Printed Circuit Board, they are reinforced but you should still be gentle when plugging in your peripherals, or you might end up having to get a visit from your friendly neighborhood TV repair man.
Here we have a close up of the defective power board were going to replace (bad power board!) You can see the two high voltage power supplies that up the household 120 volts to the higher voltage needed to power the LCD and the back lights. To remove the power board gently(!) remove the wire connectors, then unscrew the board from the chassis. Be sure not to short out the capacitors, they might not have fully discharged yet.
Here we have the back of the LCD with the power board removed. This is the end of the removal, to put the TV back together again, follow the previous steps but do them in reverse. Put the new power board in, screw it down, connect the connectors, then put the back of the TV back on. Now before you screw all the screws back in it’s time to test the TV, you can either do this while it laying on the floor or you can flip it over on to its back and test it like that. Just plug it in, turn it on, and see if it works. Make sure you test out all the inputs to make sure everything is connected properly. If the TV does not power on it’s time to break out the multi meter and test the new power board to see if it’s defective. Most boards that are sent out are refurbished so there is a chance the board could be dead on arrival.
Good thing this TV came out okay with no problems. Once you’ve screwed all the screws into the back panel, and in this case the brackets, you are ready to go!
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