Visio VF551XVT Problem
Hi all, new here, got an issue with my TV. Searched the forum for this problem, and one was close, but it went unresolved back in 2012. And while similar, my issue is different.
So, the TV was operating, and (I get this second hand) there were two pops, and it turned off.
When plugged in, the logo lights up yellow, as normal standby mode, when you press the power button, the TV lights the LEDs above the soundbar in sequence, and then sits, the logo does not turn white and the screen does not turn on.
I checked all circuit boards and there are no obvious problems. No blown caps, no visually blown transistors, no scorch marks anywhere.
My first thought was the PS, so I probed the supply lines. the +5V standby is there, and the PSON line sits at a few tenths. When the power button is pressed, the PSON line goes to 1.3V and stays there.
Next I shorted the 5VSB to the PSON, and voila, the PS turns on fully. So it appears to work correctly.
Next I hard jumpered the +5VSB to the PSON, and plugged a source into an HDMI input. When I press the power button, the TV powers on fully, the display comes up, all menu functions work, and it plays video with audio just fine.
This would be OK, but I don't want to leave the PS on full at all times. I first thought the main board was fried, but it appears only the circuitry that drives the PSON signal is bad. Since this is a pretty complex multilayer board, I can't visually map out where this signal comes from, I'm assuming there is a dead transistor somewhere and that might be the extent of the trouble.
Is there anyone with a schematic or experience with this mainboard who can possibly help me figure out where to look? Even just knowing what the PSON circuit looks like and maybe some Reference Designators would be helpful.
I suppose I could mount a switch on the side of the TV that completes the 5VSB -> PSON circuit, but then I'd have to flip it every time I turned on the TV, and remember to flip it off when done. The mainboard is available online, for ~$230, which I'd rather not have to pay for a possible blown 2N2222 or similar.
Thanks for reading my rambling post.
--Matt
So, the TV was operating, and (I get this second hand) there were two pops, and it turned off.
When plugged in, the logo lights up yellow, as normal standby mode, when you press the power button, the TV lights the LEDs above the soundbar in sequence, and then sits, the logo does not turn white and the screen does not turn on.
I checked all circuit boards and there are no obvious problems. No blown caps, no visually blown transistors, no scorch marks anywhere.
My first thought was the PS, so I probed the supply lines. the +5V standby is there, and the PSON line sits at a few tenths. When the power button is pressed, the PSON line goes to 1.3V and stays there.
Next I shorted the 5VSB to the PSON, and voila, the PS turns on fully. So it appears to work correctly.
Next I hard jumpered the +5VSB to the PSON, and plugged a source into an HDMI input. When I press the power button, the TV powers on fully, the display comes up, all menu functions work, and it plays video with audio just fine.
This would be OK, but I don't want to leave the PS on full at all times. I first thought the main board was fried, but it appears only the circuitry that drives the PSON signal is bad. Since this is a pretty complex multilayer board, I can't visually map out where this signal comes from, I'm assuming there is a dead transistor somewhere and that might be the extent of the trouble.
Is there anyone with a schematic or experience with this mainboard who can possibly help me figure out where to look? Even just knowing what the PSON circuit looks like and maybe some Reference Designators would be helpful.
I suppose I could mount a switch on the side of the TV that completes the 5VSB -> PSON circuit, but then I'd have to flip it every time I turned on the TV, and remember to flip it off when done. The mainboard is available online, for ~$230, which I'd rather not have to pay for a possible blown 2N2222 or similar.
Thanks for reading my rambling post.
--Matt
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