vizio "pop of death" fixed, still no picture

[bigred*]

hey so i have a vizio vp50 hdtv10a which suffered the infamous pop of death, took the back off and could easily see what caps had gone bad on the power supply, ordered the repair kit and started off by only replacing the bad caps, tried to power on and heard another pop that sound like it came from around the y drive, y main area. so i took it back out and replaced all 19 caps, whether they looked bad or not. hooked it back up and now i have something. earlier the tv wouldnt even stay on, no audio or video. now the tv powers on fine and stays on, i also have audio, just no picture so i have been trying to test everything but cant figure it out

power supply board is good now, all my vs and va outputs are up to specs (193v and 68v) along with all the 5 volt outputs working properly to. i will admit, it was a sloppy solder job, i need a new gun, but it all works

zsus board i am told rarely goes bad, and i can hear a small buzzing coming from under the heat sink, which gets up to about room temp

ymain board also is producing its buzzing, its heat sinks get a little warmer then room temp
tried unplugging both of these seperatly and if unplugged the tv will remain on and i still have audio

also went and completely removed both the upper and lower y drivers seperatly, to which, when either one was out, half the tv did NOT come on, so those are good.. for now
the only thing left is that lg board that has the d1-d5 LED's on it. when the tv is on, i have never seen d1 or d2 light up, usually d3, d4, and d5 all light up, then d5 goes out, sometimes d4 will go out though, and other times all 3 remain on, i believe it has to do with the input selected on the tv. i do know that if i unplug the lg board the tv will turn on, after a few seconds the relay will click back off but the light on the front of the tv will stay green. i will admit i went to plug the lg board back in and forgot to pull the power plug, and very oddly the plastic piece used to mount the back panel of the tv in the upper right corner above the zsus board began smoking!? the plastic! there are no electronics touching it, and the smoke was NOT coming from somewhere else.. it was very odd
but put it all back together and im back where i was at, i can listen to audio all day but no video

any advice will help, if there is a better way to test something i would greatly appreciate the knowledge, thanks!

[drpj23]

Re: vizio "pop of death" fixed, still no picture

If you get a good screen with either buffer but not both, I have heard that being buffers (such as for some reason one pulls down the other but work independently of each other) I could blame Y sus but usually that results in no picture at all, but I need verification on that. If the screen is primed (glowing in a sense) then you may want to go to the controller board. But you probably don't have the panel primed from you results.

If smoke came near the Z SUS then take the board out and examine it.

Also are the ALL the fuses on the Y and Z board good?

The lights shouldn't be a big issue right now. The lights flash for various reasons one being the temp of the TV. The input selection should be independent of this board.

[tom66]

Re: vizio "pop of death" fixed, still no picture

Y-sus is only involved in lighting up the screen, making pixels change quickly, and controlling the priming. So if you have a lit up screen or partial picture, your Y-sus is most likely working.

The buffer chips pass data along to each other. When one goes bad the chain stops so all other buffers get no signal.

[bigred*]

Re: vizio "pop of death" fixed, still no picture

ya so i am not getting any glow at all, if i remember right, the y sus does the picture like said above and z sus controls the brightness i think, correct? the smoke, i spent forever examining that zsus board just in case, and i saw nothing, it was completely baffling

so i dont get any form of screen at all whether with either buffer alone or both together, the screen is never primed. What i dont get is i was told to take each buffer out to check if the other one is working, but it looks like the signal runs through the top buffer to get to the bottom buffer, which describes that chain tom66 mentioned, so if my bottom buffer is ok and only the top one is bad how would i check that? do i leave the signal in but pull the ribbon cables and the chip so the back of the chip isn't grounded out, or is there no way to check?
the fuses all checked out, both on the y sus board and the one on the power supply, they're the white ones, so you cant visually check them, but with my multi meter, i got i think .2ohms across all them, so they're ok.. are there more fuses i may have over looked or is it just the 3 because i dont believe i saw one on the z sus board?
thanks for the help guys