Loud pop. Power remains but screen unresponsive

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Vizio GV47L LCD

Rep: 11

Postado: 18 de jan de 2020

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Loud pop. Power remains but screen unresponsive

Old Vizio LCD, worked fine until I heard a loud pop. The screen went blank but I can still see the backlight shine from the edges, however after I reset the TV the back light wont work even though TV seems to turn on. The only damage I see to the board is in the picture, these components within the brown patch move when I touch them with the leads probably fried underneath because I hear cooked plastic. The shield is fixed on the board and I'm a little worried removing the bored but through it I see no damage to the caps or other components. Fuse is fine also. What is this damage and how bad is the situation? Is TV done?

Vizio LCD GV47L FHDTV10A

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jayeff @jayeff

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Postado: 18 de jan de 2020

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Hi @nourarnaout ,

See if you can find a board number printed on the power board somewhere.

It might be something like 0500-0507-0260 or similar.

Work out if the problem components are on the "hot" side of the power board or the “cold” side.

The hot side is usually where the AC supply comes in and on a lot of boards they actually mark the board with a line either side of which is marked hot and cold.

Just a quick check as usually if a component goes on the hot side replacing the board is the most effective way of repair.

If it is on the cold side it may be a problem further into the TV that affected the power board so to speak. It still could be the power board but perhaps not.

Once you have found the powerboard, board number, search online for Vizio (insert powerboard, board number) to get results for suppliers of the board and if the price suits, replace it

Hi @nourarnaout ,

Yes.

You need to look for a DPS 475 AP A Rev54 schematic.

I did a quick search but came up empty. You may have better luck.

What I have found though is a service manual for the TV which may help a little. It shows that the power board number is 0500-0507-0260. Does this match what yours is?

If it is then unfortunately there there is no schematic for the board in the manual but there are a few clues which at least is a step forward

The following description is from the manual:

“The TV system block diagram is powered by power board that transforms AC source of 100V~240V AC +/- 10% @ 50/60 HZ into DC 5V & 12V& 24V source. The main board receives different types of video signal into the MTK8206 Ic. Afterward, the MTK8206 Ic process the signals control the various functions of the monitor and outputs control signal, video signal and power to the 47” WUXGA panel to be displayed.

The power send to the panel is first processed by the inverter. The function of the inverter is to step up the voltage supplied by the main board to the power that is needed to light up the lamps in the panel”

It mentions the voltages supplied by the power board, i.e. 5V, 12V & 24V and also that there is an inverter between the power board and the panel to bump up the voltage necessary for the backlight LEDs. It may be that the inverter is actually on the power board and this is the section of the board that has failed. Be aware that this is high voltage >100V DC so it places a lot of stress on the components

Sorry that’s the best I can manage at the moment.

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Of you look at the second picture These components are on the right side bored (the small shield) which is not the power supply board side (bigger shield). Ordering a board is a hassle, this TV is currently in Egypt, so it's either dump or simple component swap fix. I just need to confirm before I dump it. Thanks for your reply

18 de jan de 2020 por Nour A

Hi @nourarnaout ,

OK.

On that side is where all the power supplies go to the various sections of the TV.

Try searching online for the schematic for the board (search for "{(insert board number] schematic"} and hopefully this will help to not only identify the faulty components and their value making it easier to order replacements but should also tell you what voltages to expect at various outputs on the board.

If there are no voltage markings on the board itself it is very difficult without a schematic.

That is why I suggested a board replacement

18 de jan de 2020 por jayeff

I've added a photo. I've put the TV back together earlier but I was able to salvage this close up from the second photo. Is this what I'm looking for?

18 de jan de 2020 por Nour A

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Of you look at the second picture These components are on the right side bored (the small shield) which is not the power supply board side (bigger shield). Ordering a board is a hassle, this TV is currently in Egypt, so it's either dump or simple component swap fix. I just need to confirm before I dump it. Thanks for your reply — Nour A
Hi @nourarnaout ,

OK.

On that side is where all the power supplies go to the various sections of the TV.

Try searching online for the schematic for the board (search for "{(insert board number] schematic"} and hopefully this will help to not only identify the faulty components and their value making it easier to order replacements but should also tell you what voltages to expect at various outputs on the board.

If there are no voltage markings on the board itself it is very difficult without a schematic.

That is why I suggested a board replacement — jayeff
I've added a photo. I've put the TV back together earlier but I was able to salvage this close up from the second photo. Is this what I'm looking for? — Nour A

Vizio GV47L LCD

Loud pop. Power remains but screen unresponsive

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